[bootface]

[size="7"]Hello:

I've been playing bridge for decades but I'm new to competition bridge (BBO) and Master Points. I don't have a clue how the MP% is calculated. In a competition today, I had 12 high card points and my partner had 9. We bravely bid up to and made 4 hearts. However, the results showed that while we had earned 420 game points, our MP% was only 27.2% while the opposition got 72.8%. This doesn't seem to make any sense. In the next game, the opposition had about 28 high card points between them, they bid and made 4 spades and got 84% while we only got 16%. So, it seems you lose points for good play? Can anyone explain?

Thanks [/size]

[mgoetze]

Explanation of MP scoring

Click on "other tables" to see how your good play compared with other tables. Your 420 may well have compared poorly with some 450s for example.

[barmar]

If you've mostly played rubber bridge, you may want to play in IMP tourneys rather than MP tourneys for a while. The scoring there is more reflective of what you're used to: a big bridge score difference will result in a big IMP difference, a small bridge score difference results in a small IMP difference.

But if you're planning on playing in f2f pair tourneys, they're almost always scored MP, so you should get used to it.

[fuburules3]

Here is what I suspect is the first hand.

It appears that if you eliminate clubs (while drawing trump) and exit a diamond you can force E to lead away from his K and make 450 (or perhaps if defense is not alert, you can just lead towards Q and hope E ducks). You can see what happened at other tables here (you can find this by typing your name in "myhands" on the bbo homepage).

[bootface]

Thanks for all the responses and I now understand how match points are calculated. Nevertheless, it makes absolutely no sense. I bid and make what I bid. Why should I be penalized and my opponents be awarded for mistakes made at other tables? Okay, I can understand how these other tables have stretched another trick but only because their opponents were somewhat inadequate. Furthermore, why should my opponent get 72% for doing no more than following suit? It does not reward good bidding in any way. I'll stick to rubber bridge. The rules are a bit more logical and fair.

[Elianna]

 bootface, on 2012-April-10, 17:00, said:

Thanks for all the responses and I now understand how match points are calculated. Nevertheless, it makes absolutely no sense. I bid and make what I bid. Why should I be penalized and my opponents be awarded for mistakes made at other tables? Okay, I can understand how these other tables have stretched another trick but only because their opponents were somewhat inadequate. Furthermore, why should my opponent get 72% for doing no more than following suit? It does not reward good bidding in any way. I'll stick to rubber bridge. The rules are a bit more logical and fair.

I guess it can be looked at from the other side, too.

What if you kept getting dealt 28 HCP hands (between the two of you)? And you keep bidding and making very cold games. Why should your opponents keep getting -420 for "just following suit"?

I'm not saying match points is necessarily BETTER than rubber bridge, I was just pointing out that all is not always what it seems.

The point of matchpoints is that it compares what you do with your hands to what others do with the same exact hands.

Perhaps you might prefer International Match Points (IMPs). This still compares what you do with your hands to others, but in the example you gave the difference would only be 1.0 IMPs, which will not feel like as much, and so may feel fairer (and more similar to rubber bridge) for you.

[manudude03]

The trick at matchpoints isn't so much that it rewards good bidding/play, more like it punishes mistakes, much more so than rubber/imps. As fuburules said, 11 tricks were there for the taking (even on best defense) and it MPs scoring will usually punish you for not finding it. Sometimes it will appear as if the opponents are getting rewarded for doing nothing, but that can happen at any form of scoring, say you bid a grand slam that is cold provided trumps are not 4-0 offside and it turns out that is the case, the opponents are going to score big even though they didn't do anything except follow suit.

A common piece of advice that's given is to play for average boards and then take your gifts as you get them.

[Stephen Tu]

 bootface, on 2012-April-10, 17:00, said:

Thanks for all the responses and I now understand how match points are calculated. Nevertheless, it makes absolutely no sense. I bid and make what I bid. Why should I be penalized and my opponents be awarded for mistakes made at other tables?

On the hand in the question, you did make a mistake. You made only 10 tricks, while better declarers facing the same defense found the club elimination followed by diamond throw-in and made 11 tricks. Why shouldn't they be rewarded for finding a superior line? Why should you escape a bad score just because it was 11 tricks vs. 10 tricks, instead of 10 tricks vs. 9 tricks where your mistake would have cost you the contract?

Now, it is the case that some tables did not find the diamond lead and continuation, which leads to 11 tricks without much difficulty. In this case these declarers in essence got a gift from the defense, and get a good score while not doing anything particularly clever. The defenders are duly punished for not giving declarer a problem, but it does feel "unfair" that the declarers get a good score. There will be other hands where the opponents do something anti-percentage and get lucky due to lie of the cards, and again you get a bad score. There is still luck involved in the game, both in lie of the cards, and in getting opponents to make mistakes against you. That's why we don't have tournaments consisting of 1 board matches. But given enough boards, the lucky stuff tends to even out, and the people making better plays consistently will usually come out on top.

Quote

Okay, I can understand how these other tables have stretched another trick but only because their opponents were somewhat inadequate. Furthermore, why should my opponent get 72% for doing no more than following suit? It does not reward good bidding in any way. I'll stick to rubber bridge. The rules are a bit more logical and fair.

The thing is, the bidding is fairly routine on this hand. Why should you get a good score for reaching 4♥, when everybody else should also reach 4♥? You haven't done anything above average on the bidding on this hand. Whereas a fair number of people both matched you in the bidding *and* outplayed you in the play.

Matchpoints is generally a tougher form of the game. It rewards both accurate bidding, and accurate play, on more of the boards. Extra tricks in normal contracts are consistently rewarded, whether or not the extra trick happens to be the contract-fulfilling one. It rewards the better pairs more consistently than scoring by total points or IMPs.

To transition from rubber to matchpoints, you just have to get out of the mindset that merely bidding and making a contract is "good". You not only have to make the contract, you have to take every trick that was available (on defense as well). Duplicate bridge players are on average better than the average social rubber bridge player, you have to adjust your standards of what is considered "good". Everyone can bid 4h on the hand, everyone can make 10 tricks, and anybody good should be able to make 11 tricks. So although you now see it as having lost "points for good play", those of us with more experience see it as "losing points for sub-optimal play".

[Phil]

 bootface, on 2012-April-10, 17:00, said:

Furthermore, why should my opponent get 72% for doing no more than following suit? I'll stick to rubber bridge. The rules are a bit more logical and fair.

Sounds like you are channeling Victor Mollo

[ArtK78]

I clicked on the Explanation of MP Scoring linked to mgoetze's post above and I found it to be confusing. So I thought I would add an explanation.

At matchpoint scoring, one's score depends on a comparison between the score that you obtain on the hand and the scores the other pairs in your direction score on the hand. You score 1 matchpoint for each pair that you beat and 1/2 matchpoint for each pair that you tie. If a hand is played 11 times, the maximum number of matchpoints available is 10 (if you beat all 10 pairs, you score 10 matchpoints).

For example, suppose you bid and make 4H nonvulnerable for +420. Suppose the hand is played 5 times and the other scores by the pairs in your direction on the hand are +450, +420, +200 and +170. You tied the other +420 and beat the +200 and the +170, so you score 2 1/2 matchpoints. The amount of the difference does not matter. For example, the pair that scored +450 got one matchpoint by beating your score of +420, another for beating the other score of +420, another for beating the score of +200 and a fourth matchpoint for beating the score of +170. If the +170 were -1400, the pair scoring the +450 still only gets one matchpoint for beating that score.

On BBO, your matchpoint score is represented by a percentage of the maximum score you could obtain on a hand. So, on the example hand, you scored 2 1/2 matchpoints out of a possible 4 matchpoints, which is 62.5% of the available matchpoints.

Your score for a full session is the sum of the percentage scores on each hand divided by the number of hands played.

[barmar]

 bootface, on 2012-April-10, 17:00, said:

Thanks for all the responses and I now understand how match points are calculated. Nevertheless, it makes absolutely no sense. I bid and make what I bid. Why should I be penalized and my opponents be awarded for mistakes made at other tables? Okay, I can understand how these other tables have stretched another trick but only because their opponents were somewhat inadequate. Furthermore, why should my opponent get 72% for doing no more than following suit? It does not reward good bidding in any way. I'll stick to rubber bridge. The rules are a bit more logical and fair.

This is actually a pretty common question.

The basic problem is that the scoring method only looks at the scores, it can't tell WHY you got the score you got, and other tables got better or worse scores. On some hands you may get an overtrick by doing something brilliant, and you'll deserve the extra matchpoints. On other hands, the opponents will make a mistake, and you'll get these same extra matchpoints even though you didn't do anything special (these are called "gifts"). You may bid and play perfectly, but get a bad score because the opponents found the right lead on a total guess. And sometimes you'll make a mistake, but so will your opponents, and they'll cancel out and you'll get an average, even though you "deserve" a poor score.

But unless we decide to replace matchpoint scoring with judges who examine the play and decide who actually played "better", the best we can do is look at the scores. While some hands may seem unfair, in the long run better play is rewarded. There are players who consistently do well, so they must be doing something right -- it's not as random as it seems at first.

Matchpoint scoring happens to be very sensitive to small differences in score, so the slightest mistake or a random choice can have a significant effect. As we said earlier, if you don't like this, play IMP games. Knockouts and Swiss Teams are scored using IMPs, and small score differences are not as significant; they're much more like rubber bridge in this respect. They're still duplicate, so you don't have to worry so much about whether the cards are running your way or not -- if you have bad cards, your teammates will have good ones.

[Bbradley62]

 barmar, on 2012-April-09, 16:10, said:

If you've mostly played rubber bridge, you may want to play in IMP tourneys rather than MP tourneys for a while...

Or permanently. If you play in the Main Bridge Club, you can choose to play IMPs instead of matchpoints, and there are enough IMP pairs tournaments as well.

This story has been told frequently, but I thought it fit here.

Classic Bridge Quotes by Jared Johnson said:

Bob Hamman, a world champion, puts it this way: What is the difference between IMPs and Matchpoints? Who do you think were the two best heavyweights who ever fought? I don't really care who you pick, but take those two fighters, both at the peak of their careers, put them in a ring and let them slug it out for 15 rounds. Whoever wins is the champ. That's IMPs. Now take the same two fighters, blindfold them and tie one hand behind their backs. Divide the ring diagonally with a solid barrier and put a heavyweight on each side of the barrier. Now go down to the local tavern and collect 20 drunks. Place 10 drunks on each side of the ring and let the fighters go at it. Whoever knocks out his drunks first is the winner. That's matchpoints!

[Vampyr]

 Stephen Tu, on 2012-April-10, 17:32, said:

Matchpoints ... It rewards the better pairs more consistently than scoring by total points or IMPs.

Do you really think so?

[Stephen Tu]

 Vampyr, on 2012-April-13, 17:57, said:

Do you really think so?

Absolutely.

Keep in mind that people have a bad habit of conflating "matchpoints" with "pairs", and "IMPS" with "teams", since that is how each is usually scored. But it is perfectly possible to have pairs competitions scored with IMPs (very common online, less common offline), or even total points (in theory, I've never seen it). Likewise it's possible to score teams "board-a-match" aka "point-a-board", although this is rarer than IMP pairs. I hear you people in Europe also have a hybrid of the two "patton" scoring.

In any case, when you score by IMPs, you have the effect of cutting down the number of decisive boards by a lot. There are lots of boards where there is only the chance of an extra overtrick/undertrick or not, they matter almost nothing in the long run. One 50/50 slam swing based on total luck can swing 26 imps, which takes multiple game swings to recover, and even more partscore swings. Whereas MP tends to even out the importance of all the boards, so it give good players many more opportunities to display superiority.

So MP has less luck involved than IMP, in general. However the luck factor in pairs is substantially greater than the luck factor in teams where you have control over what happens at both tables, which overcomes the MP vs. IMP factor. So in terms of "best people usually winning", the order is, from least luck to most:
1. MP teams (e.g. the Reisinger, BAM teams in the fall NABC)
2. IMP teams
3. MP pairs
4. IMP pairs

You see upsets in Vanderbilt/Spingold type KO all the time; some lesser regarded team goes deep with some regularity. But look at Reisinger finals and you always see the teams with great historical records at top (or younger teams that will soon also be crushing the other competitions). People know that it is hardest to win the Reisinger so that is why many lesser teams now enter the concurrent national Swiss where they rightly feel they have better chance to win, and Reisinger is so much smaller than it used to be.

[Cthulhu D]

 Stephen Tu, on 2012-April-13, 18:22, said:

In any case, when you score by IMPs, you have the effect of cutting down the number of decisive boards by a lot. There are lots of boards where there is only the chance of an extra overtrick/undertrick or not, they matter almost nothing in the long run. One 50/50 slam swing based on total luck can swing 26 imps, which takes multiple game swings to recover, and even more partscore swings. Whereas MP tends to even out the importance of all the boards, so it give good players many more opportunities to display superiority.

It boils down to how much does facing one of the best pairs in the room who have a very difficult decision that they get right wreck your score. At butlered IMPs it can be very difficult to claw it back.

[ggwhiz]

I came to duplicate from a rubber bridge background and was advised by those that went before me to just play my (rubber) game and hope for the best while taking note3 of the differences.

Good advice that and I eventually learned to take 75% double finesses for an overtrick at risk of going down and how the game really is a test of skill with the luck element thrown in. A bit of a different animal but challenging and rewarding.

[Statto]

Safety plays tend not to occur in MPs, but are important at IMPs. As GGWhiz says, they are different animals, but you can't dismiss one as being more lucky than the other, because in the long term the luck balances out. Possibly you can get more lucky short term in IMPs, but the Bermuda Bowl is played over a large number of boards, I think at least 88 per match in the latter stages.

But do we really want to eliminate luck altogether? The soccer world cup usually involves some minnows getting to the quarter final, whilst one of the favourites is knocked out, but captivates the audience. We could change the scoring system, e.g. awarding points for goal attempts, possession, corners, etc. as an attempt to eliminate luck, but it would change the game and make it less interesting for the spectators.

Edit: removed silly final sentence.

This post has been edited by Statto: 2012-April-16, 13:52

[mgoetze]

 Statto, on 2012-April-15, 21:56, said:

Also, it would be ridiculous to play board-a-match in an 88 board teams game...

-1

[Statto]

 mgoetze, on 2012-April-16, 05:57, said:

-1

Good point. Don't know why I said that . Obviously it's not ridiculous if you want a long teams game with matchpoints strategy.