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Matchpoints and the field

#1 User is offline   CSGibson 

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Posted 2012-July-29, 20:00

One of the most common pieces of advise I hear to other good cardplayers, and one of the biggest criticisms at matchpoints is that someone will be making an "anti-field" bid or play.

If you are convinced that your judgement is better than the field's, why wouldn't you back that judgement and make the anti-field bid and play? Don't you rate to win more points in the long run by backing your judgement? Are matchpoints won in the bidding worth less then matchpoints won in the play, somehow? Is there a legitimate reason for criticizing something as anti-field beyond that the actions are high variance? And can you really win a national pairs event without taking high variance, but percentage actions?
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#2 User is offline   Phil 

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Posted 2012-July-29, 20:37

Reminds me of a lead problem I had in this same LM qualifier I've been discussing:

T9xx 87 J A9xxxx. 2N 3 3 3N. Your judgement says a heart but you know the sheep are leading a club.
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#3 User is offline   quiddity 

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Posted 2012-July-29, 20:49

What kind of response are you hoping to get? I certainly think it's reasonable to pass up a high variance action with a tiny edge if you can hope for a larger edge later in the hand or the event.
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#4 User is offline   Leo LaSota 

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Posted 2012-July-29, 21:00

View PostCSGibson, on 2012-July-29, 20:00, said:

One of the most common pieces of advise I hear to other good cardplayers, and one of the biggest criticisms at matchpoints is that someone will be making an "anti-field" bid or play.

If you are convinced that your judgement is better than the field's, why wouldn't you back that judgement and make the anti-field bid and play? Don't you rate to win more points in the long run by backing your judgement? Are matchpoints won in the bidding worth less then matchpoints won in the play, somehow? Is there a legitimate reason for criticizing something as anti-field beyond that the actions are high variance? And can you really win a national pairs event without taking high variance, but percentage actions?


A player can win any given matchpoint bridge session by making "anti-field" bids and plays if luck is on their side and they also receive enough gifts (i.e. mistakes from the opponents). Over the long run, the regular names that you see in the winner circle are terrific at the key to matchpoints. The top experts regularly make fewer mistakes than their opponents, and they take advantage when their opponents make mistakes against them.

It is true that there are situations in which an expert makes a non-standard bid or play because they have more knowledge and experience with certain bidding and play situations also.
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#5 User is offline   aguahombre 

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Posted 2012-July-29, 21:05

View PostPhil, on 2012-July-29, 20:37, said:

Your judgement says (do one thing).... but you know the sheep are (doing something else).

I was going to introduce the possibility one's degree of respect for the field might enter into a decision. We now know the esteem in which you hold the field.
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#6 User is offline   Phil 

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Posted 2012-July-29, 22:01

Yeah the field drools, especially on Day 1.

Isn't this assumed for this discussion?
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#7 User is offline   chasetb 

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Posted 2012-July-29, 22:25

Justin Lall, in one of his posts on his blog, talked about earlier in his career, when he would play in a big multi-day pairs event, he would always make Day 2 or 3, but in the finals his score would plummet. He said this was because he would be aggressive, and he would get away with it in the first sessions. Against the better/best players though, they would always punish him for it.

I tend to play the field, but if I am SURE my judgment is better than the fields, then I'll back my judgment. Of course, this doesn't always pay off. An example was in Gold Rush pairs, I declared a 4 contract, LHO overcalling 2 (she was favorable). I had 25 HCP, but I was missing the Ace and Queen of Clubs, the Queen of Spades, the KQJ of Hearts, and a Jack of Diamonds. Anyway, I played everything wrong because she had overcalled on a 3522 9 HCP hand, and went down trying for a simple Heart-Club squeeze rather than the successful finesse of the Q. Of course, DD makes 5, and most of the field made 4.
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#8 User is offline   akwoo 

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Posted 2012-July-29, 22:34

An example to think about. Let's say there are 4 possible results on a hand as you see it, A>B>C>D.

The anti-field line results in either A or D depending on the lie of the cards. (Obviously, A is more likely; otherwise you wouldn't think about this.)

The with-field line results in B if you play well and C if you don't. You play well, so you will never get C; only B if you take the with-field line, A or D if you don't.

Suppose 20% take the anti-field line, and of the remaining 80%, 40% will get B while 40% get C.

If A happens, the gain from the anti-field line is 30% (90% vs. 60%). If D happens, the loss from the anti-field line is 70% (80% vs 10%).

This means you should take the anti-field line only if A is more than 70%! Many anti-field plays are >50%, but not many are >70%! (The field isn't that bad!)

Now, if you are not an expert and end up getting C some of the time, the odds change. If you mess up and get C 25% of the time, then you still need the anti-field line to work 60% of the time - still fairly unlikely.

Essentially, the problem is that if you can get 60% by playing with the field, then you need an anti-field top or zero action to work 60% of the time to be worth it. In general, you'd need the anti-field action to help you 1.5 as often as it hurts you.

I personally take quite a few anti-field actions, but then again I'm not good enough to be a 60% player anywhere but my local club. If I really cared to win club games, I'd cut out the anti-field actions there.
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#9 User is offline   nigel_k 

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Posted 2012-July-30, 01:01

View PostCSGibson, on 2012-July-29, 20:00, said:

One of the most common pieces of advise I hear to other good cardplayers, and one of the biggest criticisms at matchpoints is that someone will be making an "anti-field" bid or play.

If you are convinced that your judgement is better than the field's, why wouldn't you back that judgement and make the anti-field bid and play? Don't you rate to win more points in the long run by backing your judgement? Are matchpoints won in the bidding worth less then matchpoints won in the play, somehow? Is there a legitimate reason for criticizing something as anti-field beyond that the actions are high variance? And can you really win a national pairs event without taking high variance, but percentage actions?

Sometimes you should and sometimes you shouldn't. But the stronger you are relative to your opponents, the higher the probability of success you need. This can be illustrated with a simple example.

Say there is a 'normal' contract that the field will play and a 'superior' contract. Let's assume that if you choose the superior contract, you will get a top 57% of the time and a bottom 43% of the time. If you play the normal contract, your result will depend on your card play and opponents' defence. If your expectation against these opponents is 55% when playing a normal contract then you maximize your score by playing the superior contract. If your expectation is 60% when playing a normal contract then you maximize your score by playing the normal contract.
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#10 User is offline   lalldonn 

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Posted 2012-July-30, 01:04

I'm confident enough in myself that I try very hard to avoid bad scores during the qualifying games and save the higher variance actions for the finals. On the last day I am going for the win, which doesn't mean I'm insane or just creating action, but I will definitely take more risks. For example, in qualifying if I like my contract I won't take a 4 to 3 finesse that risks losing extra tricks if it loses, I'll just make it and probably score fine for taking what I had coming to me.

Something I think people overlook is you rarely know what the field is doing as well as you think you do. Suppose you are on lead with some hand against your partner passing, RHO opening 1NT (15-17), you pass, LHO raises to 3NT. You are with the field so far, right? Well, how many of those precision pairs play 14-16 notrump? How many weak notrump pairs are out there? Maybe some of them don't open 1NT with a five card major. Some people bid stayman on some 4333 hands and others don't. Some will have bid puppet stayman. Maybe some people with your partner's hand opened a preempt that is too aggressive for you. You just never know what "the field" is doing. That's why I think most of the people who worry about this topic at all (which many don't) worry about it too much.
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#11 User is offline   rhm 

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Posted 2012-July-30, 02:51

View Postlalldonn, on 2012-July-30, 01:04, said:

I'm confident enough in myself that I try very hard to avoid bad scores during the qualifying games and save the higher variance actions for the finals. On the last day I am going for the win, which doesn't mean I'm insane or just creating action, but I will definitely take more risks. For example, in qualifying if I like my contract I won't take a 4 to 3 finesse that risks losing extra tricks if it loses, I'll just make it and probably score fine for taking what I had coming to me.

Something I think people overlook is you rarely know what the field is doing as well as you think you do. Suppose you are on lead with some hand against your partner passing, RHO opening 1NT (15-17), you pass, LHO raises to 3NT. You are with the field so far, right? Well, how many of those precision pairs play 14-16 notrump? How many weak notrump pairs are out there? Maybe some of them don't open 1NT with a five card major. Some people bid stayman on some 4333 hands and others don't. Some will have bid puppet stayman. Maybe some people with your partner's hand opened a preempt that is too aggressive for you. You just never know what "the field" is doing. That's why I think most of the people who worry about this topic at all (which many don't) worry about it too much.

I agree the whole subject tends to be overblown.
What wins is good bridge and avoiding simple mistakes, not trying to guess what "the field" does.
Maybe in one out of 5 deals a bridge action may be affected by the scoring and the conditions of the contest.
The vast majority of deals are not affected by it at all.

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#12 User is offline   rhm 

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Posted 2012-July-30, 03:22

View Postlalldonn, on 2012-July-30, 01:04, said:

I'm confident enough in myself that I try very hard to avoid bad scores during the qualifying games and save the higher variance actions for the finals. On the last day I am going for the win, which doesn't mean I'm insane or just creating action, but I will definitely take more risks. For example, in qualifying if I like my contract I won't take a 4 to 3 finesse that risks losing extra tricks if it loses, I'll just make it and probably score fine for taking what I had coming to me.

Something I think people overlook is you rarely know what the field is doing as well as you think you do. Suppose you are on lead with some hand against your partner passing, RHO opening 1NT (15-17), you pass, LHO raises to 3NT. You are with the field so far, right? Well, how many of those precision pairs play 14-16 notrump? How many weak notrump pairs are out there? Maybe some of them don't open 1NT with a five card major. Some people bid stayman on some 4333 hands and others don't. Some will have bid puppet stayman. Maybe some people with your partner's hand opened a preempt that is too aggressive for you. You just never know what "the field" is doing. That's why I think most of the people who worry about this topic at all (which many don't) worry about it too much.

I agree the whole subject tends to be overblown.
What wins is good bridge and avoiding simple mistakes, not trying to guess what "the field" does.
Maybe in one out of 5 deals a bridge action may be affected by the scoring and the conditions of the contest.
The vast majority of deals are not affected by it at all.

Rainer Herrmann
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#13 User is offline   paulhar 

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Posted 2012-July-30, 07:57

View PostPhil, on 2012-July-29, 22:01, said:

Yeah the field drools, especially on Day 1.

Isn't this assumed for this discussion?

Are we all better than this drooling field? Maybe the rest of you can guarantee qualifying by simply sitting back and doing nothing on Day 1, but if this is a national event, I'm not good enough to do that. (I've won a few regional events - and I still think that.) I don't pretend to think that I'm good enough to get anything more than 50% by taking what I feel is the 'field' action, so if my judgment says that I can get 53% by taking an anti-field bid, I take it. If I don't qualify, well, then I wasn't going to win the event anyway.

I take it one step further. With nine cards missing the queen, I'll use the flimsiest of evidence from the bidding or play to finesse one opponent for the queen if I think my success rate will be more than the teeny advantage offered by playing for the drop. My answer is to the first post is - 'Make what you think are your best bids and plays, and to heck with the field.'

OK, I must admit that if I'm playing against the only weak pair in a strong field, that I'll think twice before passing a bid out or making a more outrageous preempt than the field, but thinking about these things on every deal will use brainpower that will be more needed on the play and defense on difficult deals.
I tend to lead fourth best - as opposed to the best suit, the second best suit, or the third best suit for our side
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#14 User is offline   rogerclee 

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Posted 2012-July-30, 21:59

At all levels of matchpoints, the name of the game is avoiding simple errors, mostly in the play. Obviously it is a good idea to have an idea of what the field is doing, but this applies mostly to play problems IMO. I very seldom consider what the field action will be on a hand in the bidding.
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#15 User is offline   rogerclee 

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Posted 2012-July-30, 22:05

View PostPhil, on 2012-July-29, 20:37, said:

Reminds me of a lead problem I had in this same LM qualifier I've been discussing:

T9xx 87 J A9xxxx. 2N 3 3 3N. Your judgement says a heart but you know the sheep are leading a club.

FWIW it would not occur to me that anything except a club is the percentage lead, I guess I am a sheep!
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#16 User is offline   awm 

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Posted 2012-July-30, 22:23

One thing that's useful is to keep in mind in the auction is how you rate your play and defense relative to the field. For example, suppose I have the option to take a sacrifice that I'm pretty sure the field will not find, and I figure this sacrifice will get me a top board 60% of the time and a bottom board 40% of the time. Should I do it? The question that comes up is how my defense compares to the field. If I think partner and I defend better than most, we may be able to expect a 65% board by simply defending a trick better, in which case taking the sacrifice is actually wrong even though it's greater than 50/50. Of course, the opposite can also be true (if I defend worse than the field, even a sacrifice that is slightly anti-percentage might be worth avoiding the average-minus I rate to score up on defense).

Usually it is not worthwhile to think too hard about "what the field will do" -- but I do think it's worth considering your expected score before taking a high-variance action (especially in the auction).
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#17 User is offline   gnasher 

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Posted 2012-July-31, 02:25

phil said:

Your judgement says a heart but you know the sheep are leading a club.

rogerclee said:

FWIW it would not occur to me that anything except a club is the percentage lead, I guess I am a sheep!

That's quite a good illustration of why "field considerations" are usually not worth considering. There is so much variation in people's judgement that usually there isn't anything that could be defined as the "field action".
... that would still not be conclusive proof, before someone wants to explain that to me as well as if I was a 5 year-old. - gwnn
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#18 User is offline   phil_20686 

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Posted 2012-July-31, 03:49

View Postrogerclee, on 2012-July-30, 22:05, said:

FWIW it would not occur to me that anything except a club is the percentage lead, I guess I am a sheep!


You can add me to the list of sheeple :)
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#19 User is offline   aguahombre 

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Posted 2012-July-31, 11:03

I would feel sheepish if I led a heart and the mama-papa lead would have kept us in contention.
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#20 User is offline   Phil 

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Posted 2012-July-31, 11:12

View Postaguahombre, on 2012-July-31, 11:03, said:

I would feel sheepish if I led a heart and the mama-papa lead would have kept us in contention.


Yup. Have had good results not leading entryless minor six baggers at MPs. Well, not every time obv.

P.S. pard had KJTx.
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