Matchpoint Expectation Question Unsettle a Bet
#1
Posted 2007-April-30, 22:37
My partner says we should expect a very poor MP score because I made an anti-field anti-odds decision that did not work out while most of the field will have better scores. (We were -50 and that does lose to +120, which my partner thinks is the normal score, so my partner might have somewhat of a point.)
I say that we would have had a good score had the game made (and would have if the finesse would've won), +400 would've been better than +150 had the game made, and we might still get a good board anyway.
So, who'se right? Should I expect a good (or at least average board). Or, is my partner right?
Thanks!
#2
Posted 2007-April-30, 23:09
For arguments sake, lets say you upgraded a 14 count to a 1N opening and your pard put you in 3N with a good 9 or 10.
The hands mesh well, but game is dependent on a finesse, which loses.
I'd say you can look forward to about a 10-20% score on this board. You would have had an 80-90% score if the hook won.
If variance is your thing, then go for it. But if you want to keep you results in the 40-60% range on hands like this, you should play with the field.
#3
Posted 2007-April-30, 23:16
Was the bottom to be of any surprise? Or, would a good board have been a surprise?
#4
Posted 2007-May-01, 01:40
You say that you expect the field to be in 1NT. By that premise, it's obvious that you'll get a near top for making 3NT and a near bottom when you go down.
This is rather obvious if you make an anti-field action. Wheter your action was wrong is hard to say, lacking the hand and bidding. The result proves that it was anti-field though.
Thus, failing in 3NT, a bottom was hardly surprising.
Harald
#5
Posted 2007-May-01, 01:50
If you do something not many people will do, and end up scoring less than a normal action would do, of course you should expect a poor score.
What is so hard to believe about that? 50% of your questions are of the approximate form "I did [something abnormal/anti-percentage] that resulted in a worse bridge score than the action most others would take. This translated to a poor [matchpoint/IMP] score. Is this surprising?"
No, it's not, and never will be. Bad scores in bridge come when you do worse than the field, and you should never be surprised about this. Good scores come when you achieve a score that you think is *better* than what most people would score, not worse. Average scores come when you think you've scored the same as most people. Certainly going minus when you think most people will be plus will never qualify as a good score. You'd expect a good score if you had made the game, and think that no one else would bid it. Being surprised at a bad score when going down in such a game is just completely illogical. MP and IMPS are directly correlated to the size of your score vs. the other pairs. If your score is better than most, it will be good. If it's worse, it'll be bad.
Take percentage actions, your scores will improve. Even if you manage to make 9 tricks, at MP it won't be necessary to bid game if it's a clear overbid; taking 9 tricks will still beat other people if they only take 8. Only expect good scores when you take more tricks than other people would in normal contracts, bid more accurately than most would, or get to abnormal contracts that score better for your side than the normal contract. Hoping for a good score when you've screwed up somehow is just kind of loony. Bridge is mostly a game of trying not to make mistakes, and doing stuff to hopefully cause the opponents to make mistakes. If you make any kind of mistake, just expect a poor score, be surprised if it turns out average, not if it comes back low. Try to make fewer mistakes in the future, that's all you can really do.
#6
Posted 2007-May-01, 03:35
AAr, on May 1 2007, 06:37 AM, said:
My partner says we should expect a very poor MP score because I made an anti-field anti-odds decision that did not work out while most of the field will have better scores. (...)
I say that we would have had a good score had the game made. So, who's right? (...)
So basically you know everyone or most will score better than you. Thus, you know that you'll get a bad score.
Your partner says you'll get a bad score. You say you would have received a good result had the game made. You're both right
The more interesting question is: is it the percentage action or a non-percentage action to bid an exactly 50% game @ MP? But this question has already been answered (in this thread also by Phil): in the long run it makes no difference, as long as the game is indeed 50% and everybody plays in the same denomination. For example 120 beats 110 regardless of the chances of 3NT.
I hope any of this helps.
George Carlin
#7
Posted 2007-May-01, 04:14
I mean, bidding this 3NT is clearly going to be a top or a bottom, nothing in between. So if the gains are 40% and the losses are 60% (you expect 60% on average) on a 50-50 decision, you took a wrong action.
Always hard to calculate how much the field will win ofcourse
#8
Posted 2007-May-01, 06:28
An example you may understand better, is a person who is playing a hand the can take a particular number of tricks, it is not important how many. The line of play selected has 2 ways to success, one line is 100% and another line is 50%, a finesse or a strip and end play. On this particular hand the hook works and the scores are therefore equal. Surely we do not believe the 50% line of play was ok only because it worked. This type of thing happens all the time and sadly many players overlook what took place because they SCORED the same. This is just about the same as a person who just played a hand in part score and made 10 tricks although the hand could have been held to 9 tricks, and they say, we should have bid game, or berate partner for failing to bid game because "other people made it" . Resulting will not help anyone learn this game.
#9
Posted 2007-May-01, 08:40
AAr, on Apr 30 2007, 11:37 PM, said:
Ok, so you know you have overbid.
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You evidently know that you are in an anti-field contract.
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My partner says we should expect a very poor MP score because I made an anti-field anti-odds decision that did not work out while most of the field will have better scores. (We were -50 and that does lose to +120, which my partner thinks is the normal score, so my partner might have somewhat of a point.)
Somewhat of a point? What part of being plus +120 is always better than being -50 are you failing to comprehend?
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Yes, you would have had either a top or close to top had 3N made but.....
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You don't have a snowballs chance in hell of receiving a good board anyway. You have already acknowledged that the majority of the field will be +120. You are -50. How many people do you expect to outscore? Very few. It isn't possible to receive a good board. Statements like this make no sense.
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Your partner is. And you should expect a terrible score for the result.
So many experts, not enough X cards.
#10
Posted 2007-May-01, 09:16
In my home club game, you might get a fairly good score. Sure, the "field" action might be 1NT, making two. However, you might beat a few people, like 4♦ redoubled down two, 1♥ the other way, doubled, making six, and 1NT down two.
-P.J. Painter.
#11
Posted 2007-May-01, 10:05
Say in a four session event I expect to make the cut, but still finish about 4 boards behind the winners if we play our normal game. That result will put us in the low overalls. We'll make plenty of judgment errors and a few mechanical errors. Plus, there's the celebrity factor. A lot of name players will get some gifts from some of the weaker players by just showing up at the table. I can't expect to get these.
A few 50-50 boards that go my way can do wonders for my scores. On the given hand, I'm guessing I will pick up 1/2 - 3/4 board by just being 'lucky' and being on the right side. If I can get 6 of these decisions right in the last two sessions, and tighten up some of our decisions, we give ourselves a chance of winning.
Gaging issues like this are pretty tough. Sometimes it just isn't a straight coin flip, sometimes by swinging you put yourself in a underdog position.
I think I heard that Greg Raymer won 28 'coin-flips' when he won the WSOP a few years ago.
#12
Posted 2007-May-01, 10:36
kenrexford, on May 1 2007, 10:16 AM, said:
In my home club game, you might get a fairly good score. Sure, the "field" action might be 1NT, making two. However, you might beat a few people, like 4♦ redoubled down two, 1♥ the other way, doubled, making six, and 1NT down two.
Under the scenario given by the OP, he "knows" that the majority of the field will likely be in 1N.
This, to me, precludes such silly contracts as 4D xx'd -2 or 1H x'd making 6. But even assuming those two results on a 12 top, you would likely have something similar to the following.
3N=......400
1N+2....150
3S=......140
1N+1....120
1N+1....120
1N+1....120
1N+1....120
1N+1....120
3D=......110
1N=......90
3N-1.....................50
4Dxx -2................600
1Hx'd+5...............?? whatever number it is.
Now score it.
Pair 1 gets 12.........100%
Pair 2 gets 11.........91.6%
Pair 3 gets 10.........83.33%
Pairs 4-8 gets 7......58.33%
Pairs 9 gets 4.........33.33%
Pair 10 gets 3.........25.0%
Our pair gets 2.......16.67%
Pair 12 gets 1.........8.33%
Pair 13 gets 0.........0%
Clearly, it cannot be right to bid 3N, when 1N+2 would have resulted in 87.5% (10-). If we make three NT, we are getting the majority of the matchpoints, even without bidding it.
We have turned a win/win situation (1N+2 or 1N+1 for an above average score in either case) into either an absolute but unlikely good result vs. a probable poor result by bidding 3N.
So many experts, not enough X cards.
#13
Posted 2007-May-01, 12:03
pclayton, on May 1 2007, 11:05 AM, said:
Say in a four session event I expect to make the cut, but still finish about 4 boards behind the winners if we play our normal game. That result will put us in the low overalls. We'll make plenty of judgment errors and a few mechanical errors. Plus, there's the celebrity factor. A lot of name players will get some gifts from some of the weaker players by just showing up at the table. I can't expect to get these.
A few 50-50 boards that go my way can do wonders for my scores. On the given hand, I'm guessing I will pick up 1/2 - 3/4 board by just being 'lucky' and being on the right side. If I can get 6 of these decisions right in the last two sessions, and tighten up some of our decisions, we give ourselves a chance of winning.
Gaging issues like this are pretty tough. Sometimes it just isn't a straight coin flip, sometimes by swinging you put yourself in a underdog position.
I think I heard that Greg Raymer won 28 'coin-flips' when he won the WSOP a few years ago.
Phil, this is all well and good, and I can even agree with you. But...you "know" you are swinging when you take this approach and that it is pretty much a top or bottom approach (in respect to this particular board).
However, the original poster leaves me with the impression that he is attempting to justify his bid on the basis of "well, I know I overbid but it might make" and "It is still possible that we can get a good score even if it goes down".
This doesn't strike me as someone who is taking a swinging approach during a session, but instead as someone who made a bad bid, and he knows he has made a bad bid, his partner knows it, and everyone else knows it, and instead of simply saying "I made a bad bid, sorry", he is now is looking for sympathy, solace, support, justifications or rationalizations for his bid.
I won't provide him with any.
So many experts, not enough X cards.
#14
Posted 2007-May-01, 13:18
bid_em_up, on May 1 2007, 08:36 AM, said:
kenrexford, on May 1 2007, 10:16 AM, said:
In my home club game, you might get a fairly good score. Sure, the "field" action might be 1NT, making two. However, you might beat a few people, like 4♦ redoubled down two, 1♥ the other way, doubled, making six, and 1NT down two.
Under the scenario given by the OP, he "knows" that the majority of the field will likely be in 1N.
This, to me, precludes such silly contracts as 4D xx'd -2 or 1H x'd making 6. But even assuming those two results on a 12 top, you would likely have something similar to the following.
3N=......400
1N+2....150
3S=......140
1N+1....120
1N+1....120
1N+1....120
1N+1....120
1N+1....120
3D=......110
1N=......90
3N-1.....................50
4Dxx -2................600
1Hx'd+5...............?? whatever number it is.
Now score it.
Pair 1 gets 12.........100%
Pair 2 gets 11.........91.6%
Pair 3 gets 10.........83.33%
Pairs 4-8 gets 7......58.33%
Pairs 9 gets 4.........33.33%
Pair 10 gets 3.........25.0%
Our pair gets 2.......16.67%
Pair 12 gets 1.........8.33%
Pair 13 gets 0.........0%
Clearly, it cannot be right to bid 3N, when 1N+2 would have resulted in 87.5% (10-). If we make three NT, we are getting the majority of the matchpoints, even without bidding it.
We have turned a win/win situation (1N+2 or 1N+1 for an above average score in either case) into either an absolute but unlikely good result vs. a probable poor result by bidding 3N.
I don't think this is a relative scatter of results.
The poster mentioned a scenario where the field took 8 tricks, but they bid 3N.
If there was some variability amongst the abilities of the declarer, and either 8 or 9 tricks were avilable, then playing the field contract, and garnering most of the matchpoints (though not an absolute top) for the uptrick makes sense.
#15
Posted 2007-May-01, 13:20
bid_em_up, on May 1 2007, 10:03 AM, said:
pclayton, on May 1 2007, 11:05 AM, said:
Say in a four session event I expect to make the cut, but still finish about 4 boards behind the winners if we play our normal game. That result will put us in the low overalls. We'll make plenty of judgment errors and a few mechanical errors. Plus, there's the celebrity factor. A lot of name players will get some gifts from some of the weaker players by just showing up at the table. I can't expect to get these.
A few 50-50 boards that go my way can do wonders for my scores. On the given hand, I'm guessing I will pick up 1/2 - 3/4 board by just being 'lucky' and being on the right side. If I can get 6 of these decisions right in the last two sessions, and tighten up some of our decisions, we give ourselves a chance of winning.
Gaging issues like this are pretty tough. Sometimes it just isn't a straight coin flip, sometimes by swinging you put yourself in a underdog position.
I think I heard that Greg Raymer won 28 'coin-flips' when he won the WSOP a few years ago.
Phil, this is all well and good, and I can even agree with you. But...you "know" you are swinging when you take this approach and that it is pretty much a top or bottom approach (in respect to this particular board).
However, the original poster leaves me with the impression that he is attempting to justify his bid on the basis of "well, I know I overbid but it might make" and "It is still possible that we can get a good score even if it goes down".
This doesn't strike me as someone who is taking a swinging approach during a session, but instead as someone who made a bad bid, and he knows he has made a bad bid, his partner knows it, and everyone else knows it, and instead of simply saying "I made a bad bid, sorry", he is now is looking for sympathy, solace, support, justifications or rationalizations for his bid.
I won't provide him with any.
If someone is looking for justification for bad bidding, I won't provide him with any either.
If I'm 'swinging', then I'm swinging, thats all there is to it. I might make a spec double trying for a good lead; or maybe trying for 200. I might psyche. I might make an anti-field 1N opening on a 4333 15.
#16
Posted 2007-May-01, 13:24
pclayton, on May 1 2007, 10:05 AM, said:
Say in a four session event I expect to make the cut, but still finish about 4 boards behind the winners if we play our normal game. That result will put us in the low overalls. We'll make plenty of judgment errors and a few mechanical errors. Plus, there's the celebrity factor. A lot of name players will get some gifts from some of the weaker players by just showing up at the table. I can't expect to get these.
A few 50-50 boards that go my way can do wonders for my scores. On the given hand, I'm guessing I will pick up 1/2 - 3/4 board by just being 'lucky' and being on the right side. If I can get 6 of these decisions right in the last two sessions, and tighten up some of our decisions, we give ourselves a chance of winning.
Well, having all 6 of these going your way is a 1.6% chance. I would rather try to play well and get a decent result as often as possible than shoot for a placing in the top 3 one out of 60 times I take part.
Edit: % typo fixed
This post has been edited by cherdano: 2007-May-01, 17:11
#17
Posted 2007-May-01, 13:32
pclayton, on May 1 2007, 02:18 PM, said:
The poster mentioned a scenario where the field took 8 tricks, but they bid 3N.
If there was some variability amongst the abilities of the declarer, and either 8 or 9 tricks were avilable, then playing the field contract, and garnering most of the matchpoints (though not an absolute top) for the uptrick makes sense.
I don't think its a relative scatter of the actual table results either. It's just some numbers I made up as a response to kenrexford's comments regarding his home game.
Of course they could easily go in a different direction, but in the context of the original post, combined with kens post, seem to be a reasonable approximation of what "could" happen, especially at ken's home game.
What probably "did" happen was:
1N+2 (one or two times) +150
1N+1 or 2N= (10-11 times) +120
3N -1 (one or two times). -50
Still the same zero or almost zero, where by just being in 1N+2 you would tie for top, and at least average for 1N+1.
That was all I was trying to point out.
So many experts, not enough X cards.
#18
Posted 2007-May-01, 13:40
#19
Posted 2007-May-01, 13:55
cherdano, on May 1 2007, 02:24 PM, said:
Arend, I swear I am seeking info here. I know you are probably better in math than I am from some of your other posts. I freely admit that I'm not a math whiz. But I don't see how are the chances of all six going "your" way equal to 60%? Is this a typo?
Assume that the odds of a contract are exactly 50%. Say there is a finesse to take, and there are 8 tricks if it loses, 9 if it wins.
Since each board was originally 50%, you would expect to make 9 tricks on three of them and 8 tricks on the other three, on overall averages.
But, aren't the odds of all 6 being right consecutively calculated as:
0.5 x 0.5 x 0.5 x 0.5 x 0.5 x 0.5 = 1.56% of actually being right 6 times in a row.
Or have I totally forgotten my statistic/probabilites calculations?
So many experts, not enough X cards.
#20
Posted 2007-May-01, 16:29
George Carlin

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