MP Strategy

[PrecisionL]

I thought inviting with an average 8 hcp (no good 5-cd suit) opposite a strong NT applied only to the old strong NT, 16-18.

 

In the 21st Century aren't students taught to invite with 9 hcp including an A or K and maybe a ten with the honor and only with 8 hcp with a chunky 5-cd suit such as: 973 742 AJ842 Kx or 973 J42 95 AK742.

 

Thanks to the ACBL Daily Bulletin from New Orleans:

 

http://www.acbl.org/nabc/bulletins/2010/02/10/ page 3

[foo]

The rule I have always taught is that an invite opposite a 15-17 1N is

a) a 9 HCP flat hand without a 5 card suit in it or

:) a 8 HCP hand with a 5+ card suit in it.

 

Judgement comes in to make sure that your HCP are actually worth what the Work Count says they are.

[bluecalm]

The rule I have always taught is that an invite opposite a 15-17 1N is

a) a 9 HCP flat hand without a 5 card suit in it or

a 8 HCP hand with a 5+ card suit in it.

 

Judgement comes in to make sure that your HCP are actually worth what the Work Count says they are.

 

Seems about right but I would change "5card suit" to "good spots". It seems 5 card suit are overrated at least my experience with simulations tells me so. Dunno how it work in real world :)

[jdonn]

Welcome back foo, I very much agree with your post.

[foo]

The rule I have always taught is that an invite opposite a 15-17 1N is

a) a 9 HCP flat hand without a 5 card suit in it or

a 8 HCP hand with a 5+ card suit in it.

 

Judgement comes in to make sure that your HCP are actually worth what the Work Count says they are.

 

Seems about right but I would change "5card suit" to "good spots". It seems 5 card suit are overrated at least my experience with simulations tells me so. Dunno how it work in real world :)

The reason the 5+ card suit is important is as follows.

 

3N makes > 50% of the time if

a) the HCP are exactly 12+12

B) there are 25 HCP and an 8+ card fit

c) there are 26+ HCP and no 8+ card fit.

 

4M makes > 50% of the time if the above is true +and+ there is a chance to gain tricks by ruffing in the short hand (or either hand if a 4-4 fit)

 

a 5+ card suit in one hand greatly increases the odds of an 8+ card fit being present.

 

As always, the caveat that the HCP above are 7/10 A & K's, that value location is average, etc etc applies.

IOW, no "white" nor "black" magic boards.

 

Good sims should verify the above.

[foo]

Welcome back foo, I very much agree with your post.

thanks. rehi to you as well and it's good to be back. :)

[awm]

In general my strategy has been to pass most balanced 8s at MP scoring. Obviously there are exceptions for hands with great spots and so forth, but I'd say that I pass most of the time.

 

Recently I've gotten some bad results from this, although part of it has been partners opening 1NT on hands where I wouldn't (recently Kx AKx KQJxxx xx for example) so perhaps this is not wholly my fault.

 

Anyway, I wanted to see what the BBF action was.

[foo]

In general my strategy has been to pass most balanced 8s at MP scoring. Obviously there are exceptions for hands with great spots and so forth, but I'd say that I pass most of the time.

 

Recently I've gotten some bad results from this, although part of it has been partners opening 1NT on hands where I wouldn't (recently Kx AKx KQJxxx xx for example) so perhaps this is not wholly my fault.

 

Anyway, I wanted to see what the BBF action was.

Kx_AKx_KQJxxx_xx

is opened 1N? (!!)

With such a nice suit, this is a 1N opening only if you are "operating".

 

Change the hand to something like

AQ_KQx_xxxxxx_AQ

(admittedly an extreme example)

...and I have a lot more sympathy with a 1N opening.

 

But when ~1/2 or more (~ 5/7.5 in this case) of the hand's tricks are in one 6+ card suit, that should not be a NT opening.

[bluecalm]

If you play standard without much gadgetry you can be in trouble after 1♦ opening lacking good rebid after 1M response so I can understand opening 1NT.

[awm]

Obviously this was a case of partner trying to turn the hands. Usually a good strategy when I'm sitting across the table, but seems to have backfired this time. ;)

 

Perhaps with more experience playing with this partner (not Elianna or any of my other usual partners) I'll know to invite a bit more aggressively than I usually do.

[foo]

If you play standard without much gadgetry you can be in trouble after 1♦ opening lacking good rebid after 1M response so I can understand opening 1NT.

Possible Standard sequences come to mind:

 

1D-1M;3D

or

1D-1M;3N

or

1D-1M;4D

 

Some pairs use 1D-1M;2C! as an artificial "catch all" for hands with 6 D's rather than 7 for jump rebids.

 

...and what hand types use which sequence is Partnership Agreement.

 

with Kx_AKx_KQJxxx_xx

a= after 1D-1S;?? I'm bidding 3N usually.

b= after 1D-1H;?? I want to use 2C! if it is available. If not, I rebid 3D.

[lmilne]

The reason the 5+ card suit is important is as follows.

 

3N makes > 50% of the time if

a) the HCP are exactly 12+12

B) there are 25 HCP and an 8+ card fit

c) there are 26+ HCP and no 8+ card fit.

So does this mean bashing with most 12's opposite a 12-14 1NT opener? I was inviting with these back in the day when I still played weak NT, and I often invite with 12 opposite an 11-14 1NT rebid.

[Cascade]

The reason the 5+ card suit is important is as follows.

 

3N makes > 50% of the time if

a) the HCP are exactly 12+12

B) there are 25 HCP and an 8+ card fit

c) there are 26+ HCP and no 8+ card fit.

So does this mean bashing with most 12's opposite a 12-14 1NT opener? I was inviting with these back in the day when I still played weak NT, and I often invite with 12 opposite an 11-14 1NT rebid.

I suspect that your strategy after a 1NT rebid should be different than after a 1NT opening irrespective of your range.

 

The auctions

 

1x 1y

1NT 3NT

 

are much more revealing than

 

1NT 3NT

 

for identical ranges.

 

This seems to suggest that the opponents will be able to defend better on the first auction than the second.

 

On the other hand at times you will have a better evaluation of your holding on the first auction.

[foo]

The reason the 5+ card suit is important is as follows.

 

3N makes > 50% of the time if

a) the HCP are exactly 12+12

:) there are 25 HCP and an 8+ card fit

c) there are 26+ HCP and no 8+ card fit.

So does this mean bashing with most 12's opposite a 12-14 1NT opener? I was inviting with these back in the day when I still played weak NT, and I often invite with 12 opposite an 11-14 1NT rebid.

"An Opening bid opposite an Opening bid means We should be in Game."

An adage as old as the "Bridge hills".

 

So

a= if you play WNTs where a minimum 1N Opening is guaranteed to be a reasonable opening bid

(see KS for a decent systemic definition- 12+ HCP, 8- losers, 2+ Quick Tricks, etc)

and

b= if you as Responder are holding a 4+ cover card 12+ HCP opening bid,

then you should GF.

 

If your partnership considers sub-minimum 11's or 9 loser 12's as an acceptable part of your 1N openings, then you have to "stiffen up" Responder's requirements for a GF.

 

...and you sacrifice the opportunity to bid odds on 24 HCP 12+12 games.

 

Nothing in life is without cost.

The price for "lighter initial action" is needing more HCP between the two hands for game to be odds on.

[gwnn]

The reason the 5+ card suit is important is as follows.

 

3N makes > 50% of the time if

a) the HCP are exactly 12+12

B) there are 25 HCP and an 8+ card fit

c) there are 26+ HCP and no 8+ card fit.

So does this mean bashing with most 12's opposite a 12-14 1NT opener? I was inviting with these back in the day when I still played weak NT, and I often invite with 12 opposite an 11-14 1NT rebid.

Absolutely. I'd always bid 3NT with 12 opp 12-14 and even if partner upgrades a significant portion of 11's. I really think being in 2NT with 12+12 or even sometimes 12+13 is not a good idea.

[gnasher]

Recently I've gotten some bad results from this, although part of it has been partners opening 1NT on hands where I wouldn't (recently Kx AKx KQJxxx xx for example) so perhaps this is not wholly my fault.

If those are the only games you're missing, it's not at all your fault. If you're treating that hand as balanced, it's worth at least 18.

[JLOGIC]

Recently I've gotten some bad results from this, although part of it has been partners opening 1NT on hands where I wouldn't (recently Kx AKx KQJxxx xx for example) so perhaps this is not wholly my fault.

If those are the only games you're missing, it's not at all your fault. If you're treating that hand as balanced, it's worth at least 18.

I don't understand treating it as balanced anyways, it's perfect for 1D then 3D. It is tough to evaluate it as a balanced hand since it's just a good hand with 6 good diamonds and a lot of playing strength...

[MartenW]

Ok, so for example holding this hand:

 

Dealer: ????? Vul: ???? Scoring: Unknown

♠ QT5 ♥ T4 ♦ KJ3 ♣ QT953

 

facing 1NT 15-17 (5card major possible) we have the following results:

 

Opposite exactly 15count available tricks (1000 simulated hands):

 

tricks:

<7 7 8 9 10 11 12 13

128 208 340 246 70 8 0 0

 

1nt makes: 872 times

2nt makes : 664 times

3nt makes: 324 times

 

opposite 16-17 count:

 

<7 7 8 9 10 11 12 13

61 121 245 315 206 51 0 0

 

1nt makes: 938 times

2nt makes: 817 times

3nt makes: 572 times

 

Let's compare passing and inviting at IMPs non vulnerable:

 

a)if we face 15 count

on 128 hands passing gains 2 imps (undertricks)

on 208 hands passing gains 4imps (90 + 50)

rest of the hands it doesn't matter.

 

Overall: 1088 imps or 1.08 imp/board

 

b)if we face 16-17count

on 61 hands passing wins 3 imps (-50 opposite - 150)

on 121 hands pasing gains 5imps (90 + 100)

on 245 hands passing gains 5imps (120+50)

on 572 hands passing loses 6imps (game versus partscore)

 

Overall: 1419imps or 1.419 imp/board

Now we have to determine how often we face exactly 15count and how often we face 16-17. According to my simulator it's: 57.4% for 16-17 and 42.6% for exactly 15.

 

So overall inviting gains 0.35imp/board.

 

Of course at matchpoints the result will be much more convincing.

Very interesting topic.

 

Since this post did not consider comparisons between all three available strategies (pass, invite, bash) I decided to calculate these strategies with the given data.

 

Assumptions:

 

The hand is as given and partner opens 1NT. Three situations are covered: matchpoints, IMPS nonvul and IMPS vul. In each situation 1/3 of the field passes, 1/3 of the fields invites with all 16-17 hands accepting and all 15 hands passing and 1/3 of the field bashes (bids 3NT).

 

Results:

 

All results are averages over all outcomes.

 

Matchpoints:

- Pass: 53.1%

- Invite: 52.2%

- Bash: 44.6%

 

NV IMPS:

- Pass: -0.51

- Invite: +0.23

- Bash: +0.28

 

VUL IMPS:

- Pass: -1

- Invite: +0.39

- Bash: +0.61

 

These results seem to suggest that indeed passing or bashing seems to be a good strategy. Inviting seems to be never the best, however if you have to stick with one strategy for both MP and IMPS then inviting is best. I'm not sure how valuable this is, considering all play is double-dummy; but inviting is clearly worse off if the play is not double dummy, since defending becomes easier. However the possibility of finding a major suit fit when is not taken into account, which sometimes makes inviting more attractive.

 

PS: NV IMPS the whole field actually loses -0.10 imp on average, this is because of the sublinear IMP curve, for example if you get +100 and two others -50, you get 3 imps while they both get -2, and imps are lost. I added +0.10 to these scores to make the average 0. Funny, I never realized that playing IMP pairs you lose imps on average.

[gwnn]

welcome to the forums!!