MP Strategy

[awm]

Suppose partner opens 1NT (15-17). Let's assume partner is fairly "down-the-middle" without too many big upgrades or downgrades.

 

You hold a balanced 8-count. Obviously things like spot cards and honor location are important here (usual hand evaluation stuff) and need to be taken into account. But I'm curious as to what people's general strategy is at matchpoints. Do you normally invite most 8s? Pass most 8s? GF most 8s? Does it depend on your perception of partner's declarer skill relative to the field? On whether you have a four-card major?

[TylerE]

In a typical matchpoint field I'm gonna invite with any 8 just because I know that's what the field is doing, and I see no real reason to deviate..

[gnasher]

I pass most 8s. The more 4-card majors I hold, the more inclined I am to bid.

 

A factor you haven't mentioned is how you'd have to invite if you did. If my methods require me to invite via Stayman, and I don't have a 4-card major, I hardly ever invite.

 

Regarding partner's ability, if partner is a much better card player than the field, I suppose you should try harder to bid with the field. I'd try to avoid that problem by finding a better game.

[gszeszycki]

the big distinction btn MP and IMPS can be summed up as follows

 

at MP invite dearly accept freely

at IMPS invite freely accept dearly

 

Since it does not pay to get into "iffy" games at mp our bidding needs to be a tad stouter than at IMPS.

 

Invite dearly means we invite wishing only to stay out of game if opener is near the

"bottom" of their range.

 

Invite Freely means we want to be in game ONLY if opener is near the top of their range (ie responder would bid game themselves if all they needed was an "average" hand from opener.)

 

The upshot of all this is that most 8 counts at mp you might as well pass saving your invites for top of the line 8 counts (like 2 aces which increases the communication between the 2 hands).

[Siegmund]

PASS. Almost all of them. All of the 4333s, and all of them without a 4-card major, for a start. When you have a 4-card major and a small doubleton, you're using 2C not so much to try to reach 3NT as to gain an extra trick playing in a major.

 

For some reason the field doesn't know this yet. And as long as the field insists on going down in one too many notrump, I will keep taking it to the bank :)

[Mbodell]

I definitely pass most flat 8s at matchpoints. Maybe if I were 44(32) I might stayman and invite over a 2♦ response, but in general, I pass.

[JLOGIC]

I almost always pass with no 5 card suit and feel strongly about it. Things that would induce me to invite rather than pass would be great spot cards, and 4 card majors combined with primed out values (which means I have a good 4M hand if we hit a fit), and aces being in my 4 card suits.

 

I pass even more often with a weak partner, which means always. It's not a big factor to me though since I think it's just right to pass, but obv if your partner is not good it's better to stay low in general when they're declaring. The field doesn't matter to me.

[Hanoi5]

I pass even more often with a weak partner, which means always.

:)

[JLOGIC]

I pass even more often with a weak partner, which means always.

:)

lol, I see how that can be read but what I meant was:

 

Since I almost always pass with a good partner, and I pass more often with a weak partner, that means I always pass with a weak partner.

[the hog]

PASS. Almost all of them. All of the 4333s, and all of them without a 4-card major, for a start. When you have a 4-card major and a small doubleton, you're using 2C not so much to try to reach 3NT as to gain an extra trick playing in a major.

 

For some reason the field doesn't know this yet. And as long as the field insists on going down in one too many notrump, I will keep taking it to the bank :)

I agree with Sigmund. Mind you, there are 8 counts and 8 counts.

[aguahombre]

I pass even more often with a weak partner, which means always.

:)

lol, I see how that can be read but what I meant was:

 

Since I almost always pass with a good partner, and I pass more often with a weak partner, that means I always pass with a weak partner.

Glad you cleared that up before Dad reads it.

[MarkDean]

I have been playing "pass or bash" for quite a while, and am reasonably happy with the results. At MPs, I will probably pass 75% of balanced 8s and GF with the others, following the same guidelines others have mentioned.

[JLOGIC]

Bashing 3N at MP seems completely terrible. Getting to 2N down 1 is better than 3N down 2. I get it at imps but just hate it at MP.

[bluecalm]

Yeah, "pass or bash" doesn't make sense at MP's.

It's approach based on argument that often contract one below game goes down anyway so shooting at very narrow target isn't profitable as if you are level higher it only costs 2/3 imps.

 

At MP's if you play 3NT instead of 2NT and the latter makes while the former doesn't you are headed for the bottom.

[Mbodell]

While I agree that pass or bash is more of a IMP strategy, it does have some gains at MP. The opening lead and other defense is different after 1nt-3nt then after 1nt-2nt-3nt or 1nt-2nt-pass. I agree that doesn't mean we should pass or bash, but it is an MP advantage to doing so.

[aguahombre]

While I agree that pass or bash is more of a IMP strategy, it does have some gains at MP.  The opening lead and other defense is different after 1nt-3nt then after 1nt-2nt-3nt or 1nt-2nt-pass.  I agree that doesn't mean we should pass or bash, but it is an MP advantage to doing so.

Yes, for the quoted reason, bashing works more often than the DD simulators will show.

 

For the same reason, the Stayman route to an invite (without a major) has drawbacks. And despite this, we still go thru Stayman (flat learning curve) when we have those 8's with which we choose to invite. Why? because we don't want to change the meanings of other responses, and we occasionally find a major suit fit anyway when Opener has 5M and a max (bids 3M while accepting after 2NT).

[Siegmund]

Even double-dummy at matchpoints, pass or bash shows a profit, at least if you evaluate by straight HCPs or any of the obvious adjustments to them. It shows a larger profit at IMPs, of course, and you bash with more hands at IMPs, because you don't need a 50% chance of a profit when the upside is so large.

 

The problem is really that we don't have a precise enough way of evaluating playing potential at notrump, and we open so many different hands with 1NT nowadays. There is just no such thing as a large body of hands that

a ) make 9 tricks more than half the time opposite a maximum

b ) make 9 tricks less than half the time opposite a minimum

but - this is the hard one! -

c ) make 8 tricks often enough opposite a minimum to justify inviting with them.

 

What happens to a lot of these 8-counts is that while they are 60% games opposite a maximum, opposite a minimum they might be 30% 9 tricks 40% 8 tricks 30% 7 tricks... such that there a small upside to getting to game (60% gain 40% loss -> net +20%), but a larger downside (70% break even 30% loss -> net -30%) to inviting and getting dropped.

 

Add to that that 1NT-2NT-3NT is defended against much more precisely than 1NT-3NT because the defenders know each others' high-card strength, and I think "pass or bash" is the way to go at either form of scoring. (I do still have an invitational sequence in my system with my regular partner - but if I am playing 2/1 with 2S->3C and 2N->3D transfers, I am DEFINITELY passing or bashing. There just aren't words to describe how hideous it is to go through 2C with an 8-count without a 4-card major.)

[bluecalm]

Even double-dummy at matchpoints, pass or bash shows a profit, at least if you evaluate by straight HCPs or any of the obvious adjustments to them. It shows a larger profit at IMPs, of course, and you bash with more hands at IMPs, because you don't need a 50% chance of a profit when the upside is so large.

 

I don't understand this. Could you please explain ? How could any method which is worse at evaluating final contract show profits considering double dummy analysis ?

 

What happens to a lot of these 8-counts is that while they are 60% games opposite a maximum, opposite a minimum they might be 30% 9 tricks 40% 8 tricks 30% 7 tricks...

 

I need to verify this. My intuition tells me that there aren't many hands of this kind.

If hand makes good game opposite maximum it usually is good enough to play 2NT opposite minimum. Do you refer to dd simuls here or to real bridge ?

 

 

Add to that that 1NT-2NT-3NT is defended against much more precisely than 1NT-3NT because the defenders know each others' high-card strength

 

I agree that it is defended more precisely. I don't agree with "much more". Opening lead is usually the same (you gotta lead a major unless having like QJTxx in a minor) and then knowledge that opener is say 16-17 instead of 15-16 doesn't help THAT much.

 

There just aren't words to describe how hideous it is to go through 2C with an 8-count without a 4-card major.)

 

Well... I played that way for some time, I've changed it with most partners to 1NT - 2NT being natural invite and stayman promising 4 card major. I don't think it's "hideous". I agree it's worse but it's not like you are giving away every board or close to it. I would say loses are relatively rare. I would much prefer to play that way at atchpoints than pass or bash. At imps I am kinda pass or bash player myself (I sometimes invite but much less than other people).

[Siegmund]

I don't understand this. Could you please explain ? How could any method which is worse at evaluating final contract show profits considering double dummy analysis ?

 

My point here was that pass-or-bash outperforms invitational sequences at double-dummy, and since the defense against pass-or-bash will be somewhat worse than against an invitational sequence, I expect pass-or-bash at the table to outperform invitational sequences by even more than double-dummy analysis predicts.

 

 

What happens to a lot of these 8-counts is that while they are 60% games opposite a maximum, opposite a minimum they might be 30% 9 tricks 40% 8 tricks 30% 7 tricks...

 

I need to verify this. My intuition tells me that there aren't many hands of this kind.

If hand makes good game opposite maximum it usually is good enough to play 2NT opposite minimum. Do you refer to dd simuls here or to real bridge ?

 

Both. I am surprised you think it would be rare. It is common for a hand to play 1 trick worse opposite a 15-HCP hand than opposite a 17-HCP hand -- if you have a 40% chance of failing in 3NT opposite 17 you will VERY often have a 40% chance of failing in 2NT opposite 15.

 

Typical percentages, aggregates from DD sims (semibalanced hands with no 8-card major fit):

17 opposite 8: 57% 9+ tricks, 30% 8 tricks, 13% 7- tricks.

16 opposite 8: 39% 9+ tricks, 37% 8 tricks, 24% 7- tricks.

15 opposite 8: 18% 9+ tricks, 37% 8 tricks, 45% 7- tricks.

 

One can try alternate acceptance rules, according to whether opener has a 5-card suit, has two tens, etc, but I've not found one yet where the 2NT bid ever showed a profit at MP.

 

Add to that that 1NT-2NT-3NT is defended against much more precisely than 1NT-3NT because the defenders know each others' high-card strength

 

I agree that it is defended more precisely. I don't agree with "much more".

 

This one is hard to quantify by simulations. My at-the-table experience is that, with a good partner, the defense from trick 2 onward is a LOT easier. Completely aside from what the simulations say, my own experience defending 1N-2N-3N is what made me convert to the bash or pass philosophy.

 

There just aren't words to describe how hideous it is to

go through 2C with an 8-count without a 4-card major.)

 

This one is a bit easier to quantify (I ran a bunch of data for this in the spring but need to write up an article on the results): the improved quality of the opening lead, all by itself, gains about 0.2 tricks per hand for the defense.

[bluecalm]

Strange. I've done some simulations of this kind and I have found that invites outperform bashing at both MP's and IMP's (but at IMPs it's negligible). I am going to make one more simul now and will post the results soon to show what I mean.

I usually assume that opener accept invite with any 16-17 while reject with every 15 because this is very close to how I play.

[junyi_zhu]

Suppose partner opens 1NT (15-17). Let's assume partner is fairly "down-the-middle" without too many big upgrades or downgrades.

 

You hold a balanced 8-count. Obviously things like spot cards and honor location are important here (usual hand evaluation stuff) and need to be taken into account. But I'm curious as to what people's general strategy is at matchpoints. Do you normally invite most 8s? Pass most 8s? GF most 8s? Does it depend on your perception of partner's declarer skill relative to the field? On whether you have a four-card major?

Well, one should usually pass with most 8 HCP hands without shortness or 5 card suits. With shortness and 4 card major(s), it's probably OK to gamble with some 8 or 7 HCP hands. Of course some 8 HCP are so good that you shouldn't treat them as 8 HCP,

AT9x AT9x xx xxx, it's probably fine to push to 3NT if you don't find major suit fit, because your T9 in majors are very important. Such kind of hands are very rare though. Also, if you hold 17, then partner would pass with normal 8 HCP balanced hands, and you still think you have a reasonable chance to make 3NT, you should open 1m then.

[bluecalm]

Ok, so for example holding this hand:

 

[hv=s=sqt5ht4dkj3cqt953]133|100|[/hv]

 

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.

[Siegmund]

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

 

Eh?

 

Opposite 15, passing wins 33.6% and ties the rest -> +33.6% net

Opposite 16-17, passing wins 42.8% and loses 57.2% -> -13.6% net

 

57.4% of -13.6 and 42.6% of +33.6 makes pass a winner by 6% per board.

 

At MP, Pass>Invite, by your own figures.

 

You appear to have found a rare hand that is Invite>Bash>Pass nonvul at IMPs. You didn't calculate the equity for bashing, but it looks like -1.23 imps/bd opposite 15, and the same +1.42 as you showed opposite 16-17, for +.29 net vs passing. Vulnerable at IMPs, it will be Bash>Invite>Pass.

 

I don't recall simulating specifically a 3-2-3-5 hand with lots of tens before. It is a topic worth investigating more -- I wonder how many other examples we can find where invites are best. (If you take all 8-counts without 4-card majors as a whole, for instance, it won't be.)

 

What restrictions did you put on opener's hand, incidentally?

[bluecalm]

At MP, Pass>Invite, by your own figures.

 

Yes, sorry I am a moron.

 

You appear to have found a rare hand that is Invite>Bash>Pass nonvul at IMPs.

 

I am not sure if it's rare. I think most great 8's and flat 9's will be in that category but that's just my guess.

 

You didn't calculate the equity for bashin

 

I calculated EV of passing vs bashing so equity of bashing vs passing is the same but with reverse sign, am I missing something here ?

 

(If you take all 8-counts without 4-card majors as a whole, for instance, it won't be.)

 

I am not surprised as with most 8counts pass so much better. I think it's better to investiga bad 9's not 8's.

 

What restrictions did you put on opener's hand, incidentally?

 

Just balanced with any 5 card suit possible. 5-4-2-2/6-3-2-2 weren't included.

[Siegmund]

I calculated EV of passing vs bashing...

 

It looked to be as if you calculated EV only of passing vs. inviting, not of raising directly to 3NT also.

 

My simulations in the past did include 5422s and 6m322s, which will increase the variance - overtricks when long suit runs, down-several disasters when a doubleton is wide open - and make exactly 8 tricks a bit of a harder target. If your results are a bit more stable, that is as it should be :P