5332 (five card major) 1NT or 1M

inquiry · August 10, 2006

I suspect that most beginners, looking at a five-card major, would not consider opening 1NT. Stipulate that the 1♥ and 1NT openers both end up playing 4♥ by opener. Of course there is a slight difference in information content because the auctions are different, but I suspect this will matter a lot less when you reach 4♥ than other contracts. How do they score? If the 1NT openers are (on average) the better players, you'll see them still scoring better despite reaching the same contract from the same side.

This hypothesis, along with MikeH's were testable. I think the data disproves Mikeh's but leaves awn still quite viable.

The following table shows the results when openers (who opened 1H) played the following contracts. The first column shows the final contract, the second column the average Imps earned, the third column the number of hands played at imps, the fourth column the average MP result, and the last column, the number of mp contracts. The opening side played 37,236 contracts out of 48,216 times they opened 1H, meaning that they played 77.2% of the contract. They averaged minus 0.309 imps on the imp hands they played (16761 hands), and 48.65% on the MP hands they played (20,475 hands).

Using this same table, we can answer the first question Mikeh posed. How did game versus part score contracts compare. When opening 1H, the part-score average was -0.606 imps (5652 hands) and 48.87% (7242 hands). The game contract (3NT, 4H, 4S, 5C, 5D) averaged -0.097 imps (9448 hands) and 49.08% (11,235 hands).

Contract	AvIMP	[space][space][space]# Imp [space] [space] [space]AvMP	[space] [space] [space]#MP
1H[space] [space] [space] [space] [space]0.92[space] [space] [space] [space] [space]372[space] [space] [space] [space] [space]59.76[space] [space] [space] [space] [space]517
1S[space] [space] [space] [space] [space]-0.34[space] [space] [space] [space] [space]5[space] [space] [space] [space] [space]53.78[space] [space] [space] [space] [space]8
1NT[space] [space] [space] [space] [space]-0.44[space] [space] [space] [space] [space]1048[space] [space] [space] [space] [space]48.43[space] [space] [space] [space] [space]912
2C[space] [space] [space] [space] [space]-1.46[space] [space] [space] [space] [space]141[space] [space] [space] [space] [space]43.13[space] [space] [space] [space] [space]113
2D[space] [space] [space] [space] [space]-0.72[space] [space] [space] [space] [space]122[space] [space] [space] [space] [space]49.65[space] [space] [space] [space] [space]134
2H[space] [space] [space] [space] [space]-0.16[space] [space] [space] [space] [space]1150[space] [space] [space] [space] [space]52.57[space] [space] [space] [space] [space]1678
2S[space] [space] [space] [space] [space]-0.14[space] [space] [space] [space] [space]401[space] [space] [space] [space] [space]47.81[space] [space] [space] [space] [space]396
2NT[space] [space] [space] [space] [space]-1.58[space] [space] [space] [space] [space]490[space] [space] [space] [space] [space]42.2[space] [space] [space] [space] [space]730
3C[space] [space] [space] [space] [space]-1.41[space] [space] [space] [space] [space]157[space] [space] [space] [space] [space]41.93[space] [space] [space] [space] [space]157
3D[space] [space] [space] [space] [space]-2.38[space] [space] [space] [space] [space]88[space] [space] [space] [space] [space]46.22[space] [space] [space] [space] [space]165
3H[space] [space] [space] [space] [space]-0.84[space] [space] [space] [space] [space]1422[space] [space] [space] [space] [space]48.12[space] [space] [space] [space] [space]2128
3S[space] [space] [space] [space] [space]-1.28[space] [space] [space] [space] [space]185[space] [space] [space] [space] [space]41.47[space] [space] [space] [space] [space]219
3NT[space] [space] [space] [space] [space]0.37[space] [space] [space] [space] [space]3257[space] [space] [space] [space] [space]53.15[space] [space] [space] [space] [space]3970
4C[space] [space] [space] [space] [space]-2.09[space] [space] [space] [space] [space]44[space] [space] [space] [space] [space]28.42[space] [space] [space] [space] [space]30
4D[space] [space] [space] [space] [space]-1.53[space] [space] [space] [space] [space]27[space] [space] [space] [space] [space]43.06[space] [space] [space] [space] [space]55
4H[space] [space] [space] [space] [space]-0.31[space] [space] [space] [space] [space]4760[space] [space] [space] [space] [space]47.34[space] [space] [space] [space] [space]6074
4S[space] [space] [space] [space] [space]-0.33[space] [space] [space] [space] [space]1174[space] [space] [space] [space] [space]45.89[space] [space] [space] [space] [space]1022
4NT[space] [space] [space] [space] [space]-0.96[space] [space] [space] [space] [space]32[space] [space] [space] [space] [space]44.78[space] [space] [space] [space] [space]30
5C[space] [space] [space] [space] [space]-0.64[space] [space] [space] [space] [space]123[space] [space] [space] [space] [space]19.98[space] [space] [space] [space] [space]46
5D[space] [space] [space] [space] [space]-1.44[space] [space] [space] [space] [space]102[space] [space] [space] [space] [space]40.08[space] [space] [space] [space] [space]93
5H[space] [space] [space] [space] [space]-1.85[space] [space] [space] [space] [space]493[space] [space] [space] [space] [space]36.66[space] [space] [space] [space] [space]636
5S[space] [space] [space] [space] [space]-3.25[space] [space] [space] [space] [space]46[space] [space] [space] [space] [space]44.72[space] [space] [space] [space] [space]60
5NT[space] [space] [space] [space] [space]-7.92[space] [space] [space] [space] [space]10[space] [space] [space] [space] [space]23.26[space] [space] [space] [space] [space]18
6C[space] [space] [space] [space] [space]-1.52[space] [space] [space] [space] [space]40[space] [space] [space] [space] [space]63.66[space] [space] [space] [space] [space]53
6D[space] [space] [space] [space] [space]-1.47[space] [space] [space] [space] [space]71[space] [space] [space] [space] [space]36.94[space] [space] [space] [space] [space]28
6H[space] [space] [space] [space] [space]1.23[space] [space] [space] [space] [space]633[space] [space] [space] [space] [space]44.7[space] [space] [space] [space] [space]594
6S[space] [space] [space] [space] [space]-1.23[space] [space] [space] [space] [space]122[space] [space] [space] [space] [space]53.4[space] [space] [space] [space] [space]182
6NT[space] [space] [space] [space] [space]-0.87[space] [space] [space] [space] [space]180[space] [space] [space] [space] [space]54.2[space] [space] [space] [space] [space]288
7C[space] [space] [space] [space] [space]1.74[space] [space] [space] [space] [space]3[space] [space] [space] [space] [space]65.35[space] [space] [space] [space] [space]4
7D[space] [space] [space] [space] [space]-6.98[space] [space] [space] [space] [space]4[space] [space] [space] [space] [space]55.28[space] [space] [space] [space] [space]5
7H[space] [space] [space] [space] [space]0.69[space] [space] [space] [space] [space]32[space] [space] [space] [space] [space]57.93[space] [space] [space] [space] [space]36
7S[space] [space] [space] [space] [space]-6.75[space] [space] [space] [space] [space]7[space] [space] [space] [space] [space]61.25[space] [space] [space] [space] [space]32
7NT[space] [space] [space] [space] [space]2.19[space] [space] [space] [space] [space]20[space] [space] [space] [space] [space]56.41[space] [space] [space] [space] [space]62

For the record, the results when the Non-opening side (dealer opens 1H) played the contract was plus +0.187 imps, and a at 49.44% matchpoint score.

How did the contracts do if you opened 1NT? This is shown in the following table. Here we see that 4♥ contract (and 3NT contract) faired much better than the same contracts if you opened 1♥ (discussed more below the table). We can also see that the both the part-score and game contracts faired better if you opened 1NT than 1♥. For example, part-scores averaged 0.286 imps (3381 hands) after opening 1NT compared to a dismal -0.606 imps (5652 hands) if you open 1H, likewise, MP partscores average 53.03% (2577 hands) if you open 1NT compared to 48.87% (7242 hands) if you opened 1♥. So mikeh was dead on correct with this part of his prediction. However, games after opening 1NT averaged 0.406 (5463 hands) and 54.56% (4308 hands) compared to -0.097 imps (9448 hands) and 49.08% (11,235 hands) for all games after opening 1♥. I will not show the table for contracts defended, but when defending after opening 1NT, the opening side averaged +0.50 imps (1880 hands) and +52.13% (1350 hands), compare that to +0.187 imps, and a at 49.44% matchpoint score after opening 1♥.

Contract	AvIMP	[space][space][space]# Imp [space] [space] [space]AvMP	[space] [space] [space]#MP
1H[space] [space] [space] [space] [space]0[space] [space] [space] [space] [space]0[space] [space] [space] [space] [space]50[space] [space] [space] [space] [space]0
1S[space] [space] [space] [space] [space]0[space] [space] [space] [space] [space]0[space] [space] [space] [space] [space]50[space] [space] [space] [space] [space]0
1NT[space] [space] [space] [space] [space]0.65[space] [space] [space] [space] [space]1796[space] [space] [space] [space] [space]55.07[space] [space] [space] [space] [space]1132
2C[space] [space] [space] [space] [space]-1.17[space] [space] [space] [space] [space]6[space] [space] [space] [space] [space]28.29[space] [space] [space] [space] [space]2
2D[space] [space] [space] [space] [space]0.64[space] [space] [space] [space] [space]11[space] [space] [space] [space] [space]44.2[space] [space] [space] [space] [space]12
2H[space] [space] [space] [space] [space]0.04[space] [space] [space] [space] [space]262[space] [space] [space] [space] [space]55.44[space] [space] [space] [space] [space]268
2S[space] [space] [space] [space] [space]0.68[space] [space] [space] [space] [space]446[space] [space] [space] [space] [space]55.85[space] [space] [space] [space] [space]298
2NT[space] [space] [space] [space] [space]-0.93[space] [space] [space] [space] [space]218[space] [space] [space] [space] [space]48.28[space] [space] [space] [space] [space]235
3C[space] [space] [space] [space] [space]0.83[space] [space] [space] [space] [space]119[space] [space] [space] [space] [space]43.48[space] [space] [space] [space] [space]90
3D[space] [space] [space] [space] [space]-0.83[space] [space] [space] [space] [space]98[space] [space] [space] [space] [space]49.12[space] [space] [space] [space] [space]93
3H[space] [space] [space] [space] [space]-0.5[space] [space] [space] [space] [space]292[space] [space] [space] [space] [space]52.04[space] [space] [space] [space] [space]293
3S[space] [space] [space] [space] [space]-1.31[space] [space] [space] [space] [space]93[space] [space] [space] [space] [space]45.98[space] [space] [space] [space] [space]106
3NT[space] [space] [space] [space] [space]0.45[space] [space] [space] [space] [space]3072[space] [space] [space] [space] [space]57.84[space] [space] [space] [space] [space]2379
4C[space] [space] [space] [space] [space]-0.2[space] [space] [space] [space] [space]26[space] [space] [space] [space] [space]49.23[space] [space] [space] [space] [space]20
4D[space] [space] [space] [space] [space]-3.98[space] [space] [space] [space] [space]14[space] [space] [space] [space] [space]46.43[space] [space] [space] [space] [space]28
4H[space] [space] [space] [space] [space]0.26[space] [space] [space] [space] [space]1201[space] [space] [space] [space] [space]50.6[space] [space] [space] [space] [space]1132
4S[space] [space] [space] [space] [space]0.68[space] [space] [space] [space] [space]985[space] [space] [space] [space] [space]53[space] [space] [space] [space] [space]662
4NT[space] [space] [space] [space] [space]-1.19[space] [space] [space] [space] [space]38[space] [space] [space] [space] [space]51.61[space] [space] [space] [space] [space]53
5C[space] [space] [space] [space] [space]-0.45[space] [space] [space] [space] [space]79[space] [space] [space] [space] [space]24.65[space] [space] [space] [space] [space]29
5D[space] [space] [space] [space] [space]-0.83[space] [space] [space] [space] [space]88[space] [space] [space] [space] [space]30.57[space] [space] [space] [space] [space]53
5H[space] [space] [space] [space] [space]-1.97[space] [space] [space] [space] [space]100[space] [space] [space] [space] [space]43.96[space] [space] [space] [space] [space]97
5S[space] [space] [space] [space] [space]-1.2[space] [space] [space] [space] [space]38[space] [space] [space] [space] [space]42.67[space] [space] [space] [space] [space]39
5NT[space] [space] [space] [space] [space]-4.54[space] [space] [space] [space] [space]2[space] [space] [space] [space] [space]38.22[space] [space] [space] [space] [space]10
6C[space] [space] [space] [space] [space]1.73[space] [space] [space] [space] [space]66[space] [space] [space] [space] [space]57.82[space] [space] [space] [space] [space]37
6D[space] [space] [space] [space] [space]0.51[space] [space] [space] [space] [space]52[space] [space] [space] [space] [space]23.73[space] [space] [space] [space] [space]19
6H[space] [space] [space] [space] [space]1.63[space] [space] [space] [space] [space]243[space] [space] [space] [space] [space]50.9[space] [space] [space] [space] [space]128
6S[space] [space] [space] [space] [space]-2.07[space] [space] [space] [space] [space]117[space] [space] [space] [space] [space]61.16[space] [space] [space] [space] [space]137
6NT[space] [space] [space] [space] [space]1.33[space] [space] [space] [space] [space]136[space] [space] [space] [space] [space]54.35[space] [space] [space] [space] [space]228
7C[space] [space] [space] [space] [space]-15.51[space] [space] [space] [space] [space]1[space] [space] [space] [space] [space]21.09[space] [space] [space] [space] [space]1
7D[space] [space] [space] [space] [space]-3.7[space] [space] [space] [space] [space]4[space] [space] [space] [space] [space]50[space] [space] [space] [space] [space]0
7H[space] [space] [space] [space] [space]-10.79[space] [space] [space] [space] [space]7[space] [space] [space] [space] [space]50.57[space] [space] [space] [space] [space]9
7S[space] [space] [space] [space] [space]-2.01[space] [space] [space] [space] [space]12[space] [space] [space] [space] [space]62.92[space] [space] [space] [space] [space]24
7NT[space] [space] [space] [space] [space]-2.55[space] [space] [space] [space] [space]8[space] [space] [space] [space] [space]65.05[space] [space] [space] [space] [space]34

So MikeH's theory is not proven, opening 1NT seems to do better across the board at part-scores, games,

inquiry · August 10, 2006

(couldnt get this in the last post.. no idea why.. continued here)

games, and when defending. But the data lends support to awm;s theory that it is because there are better players. But is this really the cause? Let's take a closer look at the 4H contracts,

When you open 1♥, these are the statistics for the 4♥ contract

IMP HANDS
4760 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge	10.01 [space] [space] 306 [space] [space] [space] -0.31 [space] [space] 24.89 [space] [space] 8.62 [space] [space] [space] 27.27
Std Err	0.01 [space] [space] [space] 5 [space] [space] [space] [space] [space] 0.06 [space] [space] [space]0.03 [space] [space] [space]0.01 [space] [space] [space] [space]0.03

MP hands
6074 [space] [space] [space]Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+DistHP+Dist[space]Avge [space] [space] [space]9.91 [space] [space] [space] [space]286 [space] [space] [space] 47.34 [space] [space] [space]24.86 [space] [space] 8.66 [space] [space] [space]27.34
Std Err	0.01 [space] [space] [space] [space] [space]4 [space] [space] [space] [space] [space] [space]0.34 [space] [space] [space] [space]0.03 [space] [space] [space] 0.01 [space] [space] [space] 0.03

When opening 1NT, these are the statistics for the 4♥ contract.

IMPS
1201 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space] 10.37 [space] [space] 414 [space] [space] [space] [space]0.26 [space] [space] [space] 24.8 [space] [space] [space] 9.18 [space] [space] [space] 27.48
Std Err [space] [space]0.03 [space] [space] [space] 9 [space] [space] [space] [space] [space]0.11 [space] [space] [space]0.07 [space] [space] [space]0.02 [space] [space] [space]0.07
[space] [space] [space]
Matchpoints [space] [space]
1132 [space] [space] [space]Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] 10.22 [space] [space] 368 [space] [space] [space] [space] 50.6 [space] [space] [space]24.93 [space] [space] [space]9.11 [space] [space] [space]27.67
Std Err [space] [space]0.03 [space] [space] [space] [space]9 [space] [space] [space] [space] [space]0.74 [space] [space] [space]0.07 [space] [space] [space] 0.02 [space] [space] [space] 0.07

Now, there is something to note here: The hands that end up in 4♥ when you open 1NT are different from the hands that end up in 4♥ when you open 1♥. What is the difference? It is not hcp (averagignn aroudn 24.85 in all cases. It is different in the number of trumps held. Note, the ones that end up in 4♥ after opening 1NT has more trumps on average. And it is the extra trump that accounts for the additional trick. Let's look more closely.

The 1H--> end in 4H occurred 10834 times and average 8.64 trumps and 9.95 tricks. The 1NT-->end in 4H occurred 2333 times and averaged 9.15 trumps and 10.30 tricks. The 1NT-->4H players had 0.51 trumps more to play with and as a result, took 0.35 more tricks. In an earlier study, an extra trump was worth 1/3 of a trick on average. This clearly suggest the "extra" trick in hearts was due not to brilliance of the players but the presenses of more 5-4 fits (on average). This suggested the following study... same opener requirement, but require responder to have four hearts, (so trumps = 9 exactly) and see how the 1NT opener versus the 1H opener faired in 4H. Here are the stats from these two studies (not trumps now = 9.0 for all conditions).

Open 1H
1623 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space]10.06 [space] [space] 347 [space] [space] [space] [space]0.07 [space] [space] [space]24.83 [space] [space] 9 [space] [space] [space] [space] [space] 27.2
Std Err [space] 0.03 [space] [space] [space] [space]8 [space] [space] [space] [space] [space] [space]0.1 [space] [space] [space] 0.07 [space] [space] [space] 0 [space] [space] [space] [space]0.07
[space] [space] [space]
Unconstrained [space]Matchpoints [space] [space]
2340 [space] [space] [space]Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space]10.21 [space] [space] [space] 355 [space] [space] [space]50.39 [space] [space] 24.93 [space] [space] 8.99 [space] [space] [space] [space]27.46
Std Err [space] [space]0.02 [space] [space] [space] [space] 6 [space] [space] [space] [space]0.52 [space] [space] [space] [space]0.05 [space] [space] [space]0 [space] [space] [space] [space] [space] [space]0.05

Open 1NT
626 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space] [space]10.4 [space] [space] 430 [space] [space] [space] [space]0.39 [space] [space] [space]25.35 [space] [space] [space]9 [space] [space] [space] [space] [space] 27.82
Std Err [space] [space] [space] 0.04 [space] [space] [space] 11 [space] [space] [space] [space]0.16 [space] [space] [space]0.09 [space] [space] [space] 0 [space] [space] [space] [space] [space]0.09
[space] [space] [space]
Matchpoints [space] [space]
684 [space] [space] Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] 10.46 [space] [space] [space]421 [space] [space] [space] [space]52.24 [space] [space] [space]25.41 [space] [space] 9 [space] [space] [space] [space] [space]28.09
Std Err [space] [space]0.04 [space] [space] [space] 9 [space] [space] [space] [space] [space] 0.92 [space] [space] [space] [space]0.06 [space] [space] [space]0 [space] [space] [space] [space] [space] 0.06

Oddly enough, the results still favored the 1NT opening, but when we forced the heart legnth to be "correct", the 1H bidders bid to game on less values by about a half of a pont, which reduced their trick taking potential. So we force one more condition. We required the team total HCP to be exactly 25 hcp. Doing so, essentially gave the two sides the same "hands". The results show the 1H openers scoring better at both imps (.59 versus 0.24) and mp (53.29 versus 51.84).

Open 1H
205 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space] [space]10.02 [space] [space] [space] [space]348 [space] [space] [space] [space]0.59 [space] [space] [space] [space]25 [space] [space] [space] [space]9 [space] [space] [space] [space]27.24
Std Err [space] [space] [space] [space]0.06 [space] [space] [space] [space]19 [space] [space] [space] [space]0.25 [space] [space] [space] [space]0 [space] [space] [space] [space]0 [space] [space] [space] [space]0.02
[space] [space] [space]
Matchpoints [space] [space]
437 [space] [space] Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space] [space]9.86 [space] [space] [space] [space]289 [space] [space] [space] [space]53.29 [space] [space] [space] [space]25 [space] [space] [space] [space]9 [space] [space] [space] [space]27.18
Std Err [space] [space] [space] [space]0.04 [space] [space] [space] [space]13 [space] [space] [space] [space]1.16 [space] [space] [space] [space]0 [space] [space] [space] [space]0 [space] [space] [space] [space]0.03
[space] [space] [space]
Open 1NT
125 [space] [space] [space]Tricks [space] [space]Score [space] [space] [space]IMP [space] [space] [space] [space]HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space] [space]10.28 [space] [space] [space] [space]408 [space] [space] [space] [space]0.24 [space] [space] [space] [space]25 [space] [space] [space] [space]9 [space] [space] [space] [space]27.24
Std Err [space] [space] [space] [space]0.08 [space] [space] [space] [space]25 [space] [space] [space] [space]0.35 [space] [space] [space] [space]0 [space] [space] [space] [space]0 [space] [space] [space] [space] [space] [space]0.03
[space] [space] [space]
Unconstrained [space]Matchpoints [space] [space]
156 [space] [space] Tricks [space] [space] [space]Score [space] [space] MP % [space] [space] HCP [space] [space] [space] Trumps [space] [space]HP+Dist
Avge [space] [space] [space]10 [space] [space] [space] [space] [space]325 [space] [space] [space] [space]51.83 [space] [space] 25 [space] [space] [space] [space] 9 [space] [space] [space] [space] [space] [space] 27.3
Std Err [space] [space]0.07 [space] [space] [space] 23 [space] [space] [space] [space] 1.92 [space] [space] [space] [space]0 [space] [space] [space] [space] 0 [space] [space] [space] [space] [space] [space] 0.05

From this, I think we can propose a new theory that might begin to explain why the 1NT opening bids with these hands work better, even on the game hands. The tables above suggest that the difference in 4H is based upon both the better fit (9 more often) rather than difference in playing skill (see the last table). For this to be true, then a prediction would exist. With a 5332 in opener and a generally balanced hand opposite including 3 card support, 3NT tends wto be a better contract. With BRidgeBRowser, that proposition is testable too.

Ben

sfbp · August 10, 2006

A co-interesting point is raised at

http://www.microtopia.net/bridge/day2.html

Do you want to play in 3NT or 4H after a 2NT opener with a 5-3 fit? This study gives RESPONDER five hearts, but it raises some of the same points.

I guess the same sort of study might be done with a 1NT opener.

A couple of advantages I would propose for 1NT opening five card majors that weren't mentioned:

a. the better range of tools for the responder (eg puppet stayman, transfers)

b. the ability to play in RESPONDER's suit at the 2 level despite opener's 5-card major.

Stephen

mikeh · August 10, 2006

Interesting :D While I think that maybe Ben misunderstood my theory, his results prove that my theory (on either view of it) was wrong! Oh well.

I was very interested to see that opening 1N was even more effective at imps on partscore hands than it was on game hands: on partscores, 1N gained about .89 of an imp per board while on game hands it gained on average only .5 imps per board. My expectation was that the per board imp gain would be a lot more on game hands than on partscores, and the evidence is to the contrary.

And I had expected that the 1N edge at matchpoints would be higher for partscores than for games, and, again, I was dead wrong :) At mps, on games, the 1N had a 5.5% edge while on partscores it was only 4.16%.

This all seems counter-intuitive to me... and it may be that the sample results are distorted by a number of factors such as awn has proposed, but so far the results look compelling. Thanks again, Ben.

inquiry · August 10, 2006

A co-interesting point is raised at

http://www.microtopia.net/bridge/day2.html

Do you want to play in 3NT or 4H after a 2NT opener with a 5-3 fit? This study gives RESPONDER five hearts, but it raises some of the same points.

I guess the same sort of study might be done with a 1NT opener.

A couple of advantages I would propose for 1NT opening five card majors that weren't mentioned:

a. the better range of tools for the responder (eg puppet stayman, transfers)
b. the ability to play in RESPONDER's suit at the 2 level despite opener's 5-card major.

Stephen

Well, oddly enough, I doubt that puppet stayman helps much when compared to simply opening 1NT. Having said that, one place where opening 1H was a clear loser was when responder's initial bid was 3♥. I presume this is due to this frequenlty being a preemptive bid. Preempting when your partner is big and balanced is probably not a good idea.

Note, just as when you can compare the average result for a first bid (like 1H or 1NT) regardless of the auction, you can look at the result of intermediate bids, like responders bids. Both 2H and 3H raises of a 1H opening bid was surprising a loser. Also auctions that went 1H-4H accounts almost entirely for the lower point count for hands that ended up in 4H on nine card fits after opening 1H when compared to hands that opened 1NT. Those 4 card preemptive raises thus may have accounted for the most of the worsing results until we forced the same HCP total.

inquiry · August 10, 2006

An interesting paradox. In trying to decide how to pursue the question of 5332 one hand opposite a three card fit for the question of 3NT or 4M better, I tested some search strategies in a small database.....

Opening 1NT was again the clear winner (final results restricted to 3NT or 4H). And 3NT with the 5-3 major fit was a run-away winner over 4H (I forced responder to have a three card fit and no singleton or void). Opening 1NT, was a huge winner (without respect to rather 3NT or 4H was reached) compared to opening 1H. But when I looked at the tricks for opening 1NT versus 1H (without regard to the final contract of 4H or 1NT), those who opened 1H took more tricks on average!!!

Here is the results...

OPEN 1NT... 
222  Tricks  Score   IMP  HCP	Trumps	HP+Dist
Avge	9.22	420	1.16	25.48	8	26.76
Std Err	0.07	19	0.32	0.08	0	0.41
     
Unconstrained  Matchpoints    
146  Tricks  Score   MP %  HCP	Trumps	HP+Dist
Avge	9.47	395	55.35	25.96	8	28
Std Err	0.1	24	2.27	0.12	0	0


OPEN 1H
383  Tricks  Score   IMP  HCP	Trumps	HP+Dist
Avge	9.64	329	-0.2	25.17	8	26.81
Std Err	0.06	17	0.26	0.09	0	0.1
     
Unconstrained  Matchpoints    
347  Tricks  Score   MP %  HCP	Trumps	HP+Dist
Avge	9.72	261	47.07	25.63	8	27.37
Std Err	0.07	18	1.62	0.12	0	0.13

The situation is, however, that if you open 1NT, you played 3NT more than 90% of the time, if you opened 1H you played 3NT only 18% of the time. The 0.3 to 0.4 extra trick was not as much value in most of the time when you opened 1H (Average score 261 and 329) compared to when you opened 1NT (average between 395 and 429). This clearly has to be related to the taking the 9 tricks on average in 3NT as compared to 4M.

But there was another paradox, one that requires futher thought before a design is set up. Playing 3NT after you open 1NT averaged 1.25 imps and 55,71%. Ok, normal enough. Playing 3NT after opening 1H, averaged 1.42 imps, but ony 48.14%. The question becomes why the worse average at MP? Does hiding openers 5 card major provide some advantage?

Do we think the advantage of 3NT over 4H (if it remains reporducible) with a 5332 pattern opposite a hand with no singleton or void will remain even if the 5332 hand is weaker and the responder hand is stronger? How should such a study to approached to avoid artificial bias as much as possible?

inquiry · August 10, 2006

Another approach... tried... I used the current bbo main room database, and search for the first 300,000 hands (all imps) with no selection criteria at all (any bid is fine). You may be interested in two findings on these hands. The first:

Opening
Bid AveIMP total hands
1C 0.03 33283
1D -0.01 31319
1H 0.01 23071
1S 0.02 23728
1NT 0.1 17390
2C 0.1 3078
2D 0.25 2174
2H 0.07 3226
2S 0.22 3224
2NT 0.27 2566
3C 0.49 1138
3D 0.02 947
3H 0 851
3S 0.31 658
3NT -1.12 171
4C 0.23 87
4D -1.67 72
4H 0.69 596
4S 0.31 456
4NT -1.16 25
5C 0.66 62
5D -0.48 59
5H -9.67 1
5S -17.13 1
5NT -12 1
6C -3.63 2
6D 1.71 6
6H 6.62 3
6S -6 4
6NT 0 0
7C -16.53 1
7D 14.67 1
7H 5.8 2
7S 0 0
7NT -18.86 2

A couple of issues, most "normal" opening bids quickly average to 0.00 plus or minus a few, see 1C, 1D, 1H, 1S above. Hands where people may, or may not bid (ike preempts) vary more, and of course, if we apply some selection factors, the values can be slanted as well. For these same 300,000 hands, I show what the different contracts averaged for the opening side (less than 300,000 obviously)...this data tells you what you already know, bidding game generally is worht more than "average" on line (see 4H, 4S, 3NT. And as bad as people think 2NT is (averages -1,25 wih lots of plays), 5NT is always a worse contract :-)

The same study can be done on millions of hands

Contract AvIMP # Imp
PO -0.02 2069
1C 0.16 348
1D -0.01 431
1H 0.47 613
1S 0.74 927
1NT 0.27 6475
2C -0.41 1226
2D -0.37 1980
2H 0.23 4013
2S 0.18 5445
2NT -1.25 3787
3C -0.8 2310
3D -0.81 3081
3H -1.05 3595
3S -1 4229
3NT 0.75 24067
4C -1.18 1139
4D -1.45 1370
4H 0.32 14164
4S 0.27 15583
4NT -1.36 358
5C -1.45 2288
5D -1.48 3009
5H -1.79 1897
5S -2.15 1545
5NT -3.79 156
6C -0.25 856
6D 0.24 1079
6H -0.52 2007
6S -0.72 2224
6NT -1.28 1840
7C -2.49 86
7D -1.68 117
7H -2.83 152
7S -0.47 161
7NT -1.49 260

Any way, having done this, I check to see what opening 1H or 1S on 5332 distribution averaged (without regards to hcp). The 1H opening with 5332 (a total of 5069 or 22% of the time. The average result of opening 1H with this pattern was -0.03, (sd of 0.03)and given the remarkably tight SD, this was "significantly" worse than opening 1He in general (0.04 with SD of 0).

what does the contract situation look like?

1H 0.2 101
1S 0.39 17
1NT 0.28 289
2C -1.67 20
2D -1.51 29
2H 0.41 363
2S 0.35 93
2NT -1.57 155
3C -1.78 24
3D -1 43
3H -1.1 332
3S -1.75 54
3NT 0.51 602
4C -2.12 11
4D -1.89 12
4H -0.08 1080
4S 0.15 171
4NT -0.41 6
5C -3.74 12
5D -1.14 25
5H -2.37 120
5S -3.41 10
5NT -7.58 5
6C -0.69 7
6D 1.19 13
6H 0.87 124
6S 0.17 37
6NT -1.78 38
7C 5.6 1
7D 5.4 2
7H -0.32 6
7S 8.47 4
7NT 4.13 7

Notice 3H and espically 4H did not fair well (remenber in general games win about 0.35 imps on line). But 3NT did very well indeed. What factors play a role in these result. BRidgeBRowser has some plotting features, so lets look at the 4H contracts,,,, using it....

First of the 1080 4H contract, responder bid 4H at his first opportunity a total of 384 times (with or without interference). 81 of those times with 3 card support. Those averaged -0.19 imps (sd 0.65). Bid 4H with four hearts a total of 135 times, averaged a nice 0.43 imps for that bid, and bid with 5 or more hearts 147 times but averaged minus 0.27 imps. But here I have run into a wall. I wold like to look at all the 4H contracts on only 8 trumps and compare to all the 3NT contracts with 5-3 heart fit. But here, in this method, I have hit a wall (avoiding any selection other than 5-3-3-2 in opener). It would be nice if there was a plotting feature that showed the total number of cards in each suit split between the partnership when you reach a final contract. We will have to ask Stephen for that!!!

inquiry · August 10, 2006

Ok.. I have examined the question of 3NT or 4M another way. I set dealer up with the following requirements.

1) 5332

2) Five spades

3) 9 or more hcp

4) A team total of 21 to 29 hcp

In addition, I required his partner to hold 3 Spades and no singleton or void (so responser is 4333, 4432, 5332, 6322 in each case with 3 Spades).

That is it, then I ran the analysis. If the 5-3-3-2 opposite no "ruffing value" is right to play in NT (at least on average), this test should show it. For this study, there was no correction for opening bid what so ever. It could be 2S, 1S, pass, 1C, 1NT, 2C, what ever. To make it handable, of course, I ran the test with the hand with five spades being the dealer. The fact that the one player only has 3S should keep wild preemptive raise of 1S mostly out of the picture.

The not surprising result, given the earlier study on hearts, was:

3NT = average 0.93 +/- 0.07 imps (3565 hands), 55.64% +/- 0.59% MP (2966 hands)

4S = average -0.22 +/-0.04 imps (11,525 hands), 45.41 % +/- 0.26% MP (10,869 hands)

Of course, this study removed the major advantage of playing in spades, as it is difficult to ruff a card in the three card suit hand with this hand pattern as responder. So we will need to repeat the same search except with responder having 3 spades and either a singleton or a void (shapes like 5431, 6331, 7330, etc). The more shape responder has with his three card fit, obviously, the more useful the 8 card fit is (can anyway say I fought the law)? I will try to do this later...

Ben

jtfanclub · August 10, 2006

Opening 1NT was again the clear winner (final results restricted to 3NT or 4H). And 3NT with the 5-3 major fit was a run-away winner over 4H (I forced responder to have a three card fit and no singleton or void). Opening 1NT, was a huge winner (without respect to rather 3NT or 4H was reached) compared to opening 1H. But when I looked at the tricks for opening 1NT versus 1H (without regard to the final contract of 4H or 1NT), those who opened 1H took more tricks on average!!!

I don't claim to understand most of this, but for that last part, there seems to be a couple of possiblities...

1. People reach game more often after a 1NT opener.

2. People end up with the contract more often after a 1NT opener (ie., 1NT openers were more likely to win the contract).

I'd be willing to bet it's the 2nd one. Would you be willing to run a test to see how many times 1♥ and 1NT openers each ended with them winning the contract, and what the result was when they didn't?

Thanks.

inquiry · August 11, 2006

Follow up study... hand opposite the 5332 hand has three card support for spades, but also has a singleton or void somewhere.

Now, the results are as one might predict... playing 4S is much, much better than playing 3NT...

3NT = -0.69 imps (488 hands) and 45.55% MP (542 hands)

4S = +0.37 imps (4401 hands) and 50.35% MP (3612)

The conclusion you might draw from this data is that if one hand is 5332 with a five card major, it is very important that the hand with 5332 be able to not only show the five card suit, but also express the "balanced" nature of the hand. The data also suggest that missing the 5-3 fit is not a bad thing when responder is relatively balanced with three card support, and if you are not worried about moysein fits, with an unbalanced responder hand yhou could still try for 4M (question this raises, how would the moysein fit do opposite an unbalanced responder?).

To take this study one step further, I made no restrictions on third seat, and had dealer hold 5S, 9 to 29 hcp, 5332 pattern, and dealer's partnership holds 21 to 29 combined hcp. There is no other restictions what so ever. Now you may have only 5 spades combined, or you may have 13. How did 3NT compare to 4♠?

3NT = 0.80 (5151 hands), 54.77% (4869 hands)

4S = -0.07 (18,185 hands), 46.93 (16,827)

Couple of issues.... remember from a few threads back, any random opening bid that ends in game wihtout some kind of restirction usually averages about 0.37 imps or so. Here 4S was both minus at imps and MP (less than 50%) when one hand held 5332 and five spades and the other hand any thing (but combined hcp 21 to 29). While 3NT was markedly better (0.80 and 54.77%).

This suggest two things.

1) don't worry so much about missing 5-3 major fit when yuou open 1NT (or 2NT) with 5332.

2) Maybe puppet stayman with balanced type hands (no singleton) is not so important opposite 2NT (or even 1NT).

I hadn't expected either of these findings when this started...

glen · August 11, 2006

This suggest two things.

1) don't worry so much about missing 5-3 major fit when yuou open 1NT (or 2NT) with 5332.
2) Maybe puppet stayman with balanced type hands (no singleton) is not so important opposite 2NT (or even 1NT).

I hadn't expected either of these findings when this started...

I'm not surprised by all this. Moving 5-3-3-2s with a 5cM into the bid handling that balanced range seems to have a small net gain, though many will remain unconvinced.

The counterpoint is that responder (i.e. the hand opposite the balanced hand type) must be able to show all singleton/voids on game going hands in order that the right game is reached. This is also criticial on hands without a five card major, as the short suit is the suit most often attacked by the defense.

the hog · August 11, 2006

From purely anecdotal evidence: I have played that all 5332 shapes in the appropriate range are opened with 1NT. We have hd very few problems with this, and the gains in the auction have been well worth it.

Ron

1eyedjack · August 11, 2006

The conclusion you might draw from this data is that if one hand is 5332 with a five card major, it is very important that the hand with 5332 be able to not only show the five card suit ...

Sorry, can you clarify please why the data shows it to be very important that the hand with 5332 be able to show the 5 card suit? I expect it is in there somewhere, but I was thinking that it might be sufficient that responder be able to show the singleton or void.

inquiry · August 11, 2006

Sorry, can you clarify please why the data shows it to be very important that the hand with 5332 be able to show the 5 card suit? I expect it is in there somewhere, but I was thinking that it might be sufficient that responder be able to show the singleton or void.

This was an extrapolation from the data that showed if partner had a short suit and 3 card support it was better to play in 4S than 3NT (the numbers were

3NT = -0.69 imps (488 hands) and 45.55% MP (542 hands)

4S = +0.37 imps (4401 hands) and 50.35% MP (3612) )

Now I neglected to show the improvement for 2S contracts. It is better to play in 2S with 5332 opposite three with ruffing value than opposite 3 without ruffing values as well. But you are correct, in general, the study showed the factor in the decision process is responders hand not openers (although the effect of a small doubleton has not been looked at yet).

pbleighton · August 13, 2006

"I don't claim to understand most of this, but for that last part, there seems to be a couple of possiblities...

1. People reach game more often after a 1NT opener.

2. People end up with the contract more often after a 1NT opener (ie., 1NT openers were more likely to win the contract).

I'd be willing to bet it's the 2nd one."

Generally agree, but I'd rather say that opening 1NT gives you an advantage in competition. You can't make a meaningful takeout double after a NT opening, and overcalls are riskier. DONT, etc., are better than passing, but don't make up for the inherent slipperiness of bidding over a 1NT opening.

And even if the opps get the contract, it may be a disaster.

The NT opener's partner also knows what to do in a competitive auction better (usually) than the 1M opener's partner.

Peter

pbleighton · August 13, 2006

Ben:

How difficult would it be to see the results when the 5cM has 7 hcp or better?

Peter

inquiry · August 14, 2006

Ben:

How difficult would it be to see the results when the 5cM has 7 hcp or better?

Peter

This is not hard at all. One can pose the questions anyway that you like. By any variable that you like.

The main problem you have to watch out for is to make sure the population of hands you examine are the same. There are two ways to do this. The forst is to describe some type of opening hand based upon hcp and shape and look at the results. For example, describing the dealer as 15-16 with 5332 and a five card heart suit. There is no selection based upon what the final results would be. ALL hands that are that shaped are examined and you only look at the final outcome (opening 11-13 hcp balanced hands 1NT seems to work out better than any other option, for example).

One way you could do this is to look for all 4H and 3NT contracts with an 8 card heart fit. But, the population of hands would not be the same. The 4H hands would include sacrafices, for example, or contracts where one partner has 8 hearts and the other a void. The program will happily give you the average tricks and average results. This select the same population of hands is very important if you are going to draw conclusions. One way to do this is to describe a combined team hcp range, and find all the contracts of interest. Then find the hands with 5-3 fits, then look at the quiality of the five card hand (make it 5332), then examine how the different responding hands opposite it did. All this can be done with one search.

Your question is a little different. I think you are asking how different hands did with from 7 hcp upwards (and 5332 with five hearts). I assume you mean in 3NT versus 4H. Of course, some of the 5332 hands will be opposite 6 hearts and a void, and will always be played in hearts, and many of them will be opposite a doubleton or less in hearts and essentially never be played in hearts. So we need to refine this search a little better. The solution ot this problem is actually quite easy but requires a slight refinement in the process.

First, describe one hand (Dealer is fine) as 5332 with 5 hearts. And give him from 7 hcp to 29 hcp. Then you might describe the team total hcp as something not outrageous. The reason to limit team is if you oare going to examine 4H versus 3NT, having 38 combined hcp would present some problems. You don't have to cap the team HCP, but I will. I will make them from 23 to 29 combined hcp, thus this defacto limits dealer to 29. Now this search will not restrict you to heart fits, so the initial search will only look at hands where opener side plays in 4H. In doing this search, I will create what is known as a "board file". All this board file is only a file with the board numbers on which A) dealer has from 7 to 23 hcp, <_< 5-3-3-2 patter with five hearts, and C) one pair at least played in 4H's. Then, I will use this board file to examine the effectiveness of 3NT versus 4H (as other contracts as well, if we like). This includes looking at the effect of 5-3 major fits versus other fits.

Next post will be the results of such a study.

ABadPlayer · August 14, 2006

Wow....great work Ben. :lol: Very intersting thread indeed.

whereagles · August 15, 2006

Wow....great work Ben. :) Very intersting thread indeed.

Indeed. Ben, you should put this in a more easy-to-read fashion and publish in a magazine :)

awm · August 15, 2006

While this is definitely interesting, I believe there was an article in the bridge world a short time ago exploring the merits of 3NT holding a 5-3 major fit. The methodology was pretty similar to Ben's and the result was that 3NT is "usually better" than 4M especially when holding two balanced hands (no singletons/voids). It seems like while the initial question was "should we open 1NT with five card majors" the answer basically came out as "yes because you're more likely to miss a 5-3 major fit and play 3NT instead, and this is better" and some of the subsequent questions have just been exploring how much better it is with different hand types.

inquiry · August 16, 2006

This is a study of contracts with 5-3-3-2 distribution in one hand, with five hearts. The other hand has from 3 to 5 hearts, and played in 4H at least once. Further, the pair of hands had a combined 25 to 27 hcp. There was no control of which side opened the bidding, how the 25 to 27 hcp were distributed between the two partners (one could have 25 the other zero, for instance). There was 862 unique deals that met this requirement in the largest online BRBR database. Further, of these there were 57,704 unique auctions (average nearly 67 plays per board ... this was from okbridge in 2001).

Without any further division of the hands (by distribution or hand opposite 5332), with from 8 to 10 card heart fit, the blanked results (without breaking down for distribution or degree of fit) were:

There was 15044 imp auctions where openers side ended up in 4H, and those hands averaged 0.24 imps, and another 14,663 auctions in 4H at Matchpoints, averaging 51.14% The non-opening side also played in 4H on these fits with 24 to 26 hcp. They ended up winning an average of more imps and more matchpoints, presumably due to the fact that few bid the games in competition I say this because the average hcp for both was 24.84 (on all the hands playing 4H, rather opener or responder.. but remember, I forced the hcp to be from 24 to 26 hcp, so hands with more or hands with less are not considered). The imps for the non-opening side in 4H was 0.84 and the matchpoints was 53.35.

There were a lot fewer hand in notrump (given I forced an 8 to 10 card heart fit, this is not surprizing). 3NT averaged +1.54 and 55.73 when this side opened, and 1.23 and 60.21 when the other side opened. And this is BEFORE controling for shortness in the hand opposite the 5332 hand. This doesn't mean all hands are created teh same, however. The average hands for 3NT was just over 25 hcp, while as noted above, the average hand for 4H was 24.84. Also there were more than Since all these hands were played in 4H at least once, I decided to further define the hands. I forced all the boards to have been played not only at east once in 4H, but also at least once in 3NT. Thus any 4H hand for which there is not at least one 3NT comparison and vise versa will be eliminated from the study. By forcing at least one hand on each board to be played in 4H and in 3NT, the number of matching hands decreased to 667 boards (down from 862 hands). And the number of unique bidding sequences reduced by 10,000 to 45,704. Of course the 3NT finall contract stats didn't change. All the reductions were in 4H contracts were no one played 3NT.

The number of 4H contracts at imps (from opener side) was reduced to 11,121, and the average result decreased to 0.05 imps, and 50.59 MP. From non opening side, 4H decreased a bit to 0.50 imps and 53.44%.

Playing with a 10 card heart fit,

at 4♥ averaged 1.03 imps and 55.44%

at 3N averaged -0.14 imps, 67.53% (but only 9 and 11 hands -- note this means only 3 actual deals in one case and two in the other. The data is not real)

Playing with 9 card heart fit,

at 4♥ averaged 0.33 imps and 52.68%

at 3NT averaged 1.6 imps and 55.55%

Next time data on 8 card heart fits, and some hcp ranges for the 5332 hand. As well as stats on hands where there is singleton or void in one of the hands (not the 5332 with hearts, of course).

ABadPlayer · August 16, 2006

I'm curious as to what difference if any it makes when using a smaller NT range (as I prefer to). I'd assume that the difference between 3NT & 4M with no ruffing values remains conistent, but what about everything else? Is it still an overall positive or do you end in enough inferior partials to negate that? How big of a difference in terms of pre-emptive value does 1N really have over 1H/1S and does that play a significant factor?

kenrexford · August 16, 2006

This post has gotten way too long to read through the entire thing each time, so please excuse me if these Q's have been asnwered.

The decision between 1NT and 1♥/1♠ as an opening, for me, has been the ability to reach games. I have been concerned about opeing 1♠ with a 15-count and hearing a 10-count 1NT and missing game, for example. Has this issue been addressed already?

In other words, I'd be curious at the frequency of a 1NT opening resulting in a 3NT/4M contract off "X" tricks, compared with the frequency of a 1M opening ending up in 4M/3NT contract of "X" tricks, compared with a 1NT opening bid to a partscore when 400/420+ was available, compared with a 1M opening bid to a partscore when 400/420+ was available.

inquiry · August 17, 2006

Data for 5-3-3-2 hands with 25-27 combined hcp, when the partnership holds exactly a 5-3 heart fit. Again for this data, someone had to play 3NT at one table and someone else had to play 4H at another to be included. There where hundreds of matching hands with thousands of plays. This allowed furhter division based on other shape issues.

Lets start with when the hand opposite the 5332 is 4333. The stats were...

4333NT IMPs

61 Tricks Score IMP HCP

Avge 8.6 263 0.34 25.01

Std Err 0.17 41 0.6 0.1

4333 NT Matchpoints

67 Tricks Score MP % HCP

Avge 8.58 201 48.3 24.91

Std Err 0.17 41 4.49 0.1

You read this from left to right. the key is the average imps (bold) and matchpoints (bold). How did this compare with the contract on the same hands in 4♥? Let's see.

4333 5332♥ IMPs

1805 Tricks Score IMP HCP Trumps HP+Dist

Avge 9.46 210 -1.08 25.15 8 26.15

Std Err 0.02 7 0.11 0.01 0 0.01

4333 5332♥ Matchpoints

2014 Tricks Score MP % HCP Trumps HP+Dist

Avge 9.36 175 44.54 25.09 8 26.09

Std Err 0.02 7 0.64 0.01 0 0.01

You may notice that in the 5332 versus 4333 with 8 card fit, the average number of tricks was higher to play in the 5-3 fit versus NT, but the net result for both matchpoints and imps favor NT. This paradox was reproducible in many different datasets.

5332 opposite 4432 (5-3 fit), played in NT (below) again had the same paradox when compared to played in hearts...

4432-5332NT IMPs

37 Tricks Score IMP HCP

Avge 8.51 266 0.61 24.67

Std Err 0.23 56 1 0.1

4432-5332NT Matchpoints

42 Tricks Score MP % HCP

Avge 8.76 254 50.42 25.04

Std Err 0.24 49 5.48 0.12

4432 [h]'s -5332 IMPs

1366 Tricks Score IMP HCP Trumps HP+Dist

Avge 9.48 236 0.23 24.81 8 26.81

Std Err 0.02 9 0.13 0.01 0 0.01

4432 [h]'s -5332 Matchpoints

1762 Tricks Score MP % HCP Trumps HP+Dist

Avge 9.67 270 51.76 25.12 8 27.12

Std Err 0.02 8 0.69 0.01 0 0.01

The 5431-versus 5332 with 5-3 fit, the statistics swing completely into favor of the 5-3 major fit. Here is the data.

5431 – 5332NT IMPs

20 Tricks Score IMP HCP Trumps HP+Dist

Avge 9.05 201 -0.44 24.75

Std Err 0.36 64 1.14 0.15

5431 – 5332NT Matchpoints

13 Tricks Score MP % HCP Trumps HP+Dist

Avge 8.38 111 40.04 24.3

Std Err 0.52 115 7.96 0.67

5431 – 5332♥ IMPs

720 Tricks Score IMP HCP Trumps HP+Dist

Avge 9.61 226 0.09 24.7 8 27.7

Std Err 0.03 11 0.17 0.02 0 0.02

5431 – 5332♥ Matchpoints

333 Tricks Score MP % HCP Trumps HP+Dist

Avge 9.69 251 48.86 25.02 8 28.02

Std Err 0.05 18 1.55 0.05 0 0.05

A couple of issues, these hand include 13 opposite 13, 5 hcp in the 5332 opposite 21 in the opposite hand and the like. That is, the fitting hands examined held 25 to 27 combined high card points, a 5-3 heart fit, ane the hand with five hearts was any 5332 distribution.

Oren Goren · September 13, 2006

The next study will examine the hands that would start 1H-2H at tables where 1 H was opened.

This may be too premature, given that I haven't finished the thread, but IMHO restricting the bidding on the heart openers to 1♥-2♥ sequences doesn't allow the full comparison.

Given that I (mis)understand the hands to be largely duplicates:

If the BridgeBrowser allows it the hand selection should be (1st and 2nd seat?) those that at some tables are opened 1♥ and at other tables 1NT - at least once each - without regard to how the bidding proceeded, including the final contract.

Certainly, the requirement of a 2♥ raise over 1♥ is not really relevant. What is it about the basic issue of ♥ versus NT that requires that limitation? What is it about the basic issue that enforces the final contract?

Is there anything in the study so far that says 1♥ is not superior in NOT reaching game?

Oren Goren

5332 (five card major) 1NT or 1M

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