players rating

[DrTodd13]

I would be in favor of a ratings system so long as there would be absolutely no way for people to see each other's ratings. I don't care how complicated the ratings system is so long as it is an accurate indicator. I don't have to understand it. Do people really believe that most people understand even the lehman system?

 

Todd

[McBruce]

Message in Bridge Base Forums, April 2006:

 

A few years ago, following a discussion on these forums, we decided to implement a rating system with the proviso that only players could ever see their own rating. We allowed tables and even tournaments with minimum and maximum rating levels. It seemed the best way to ensure that the worst aspects of rating systems were avoided.

 

We are now aware that ratings conscious people are logging on with kibitzer-bots, which keep track of who is at what table and send this information to a server which estimates people's ratings based on which tables they have been spotted at, combined with a look at a sample of the deals they have played recently and their results. Ratings are still kept private on BBO. But on several independant ratings-servers, you can find out the ratings of others, with an accuracy that is so good that there are few significant errors.

 

I don't think this is what we wanted two years ago. The question is: what do we do about it?

[red dwarf]

i am a member of a couple of other clubs(although i rarely play in either nowadays) that use ratings and the problems are many.

 

1)ratings seem to encourage "those inclined" to cheat to do so, and a few members have been caught and dismissed from one club for doing so.

 

2) you get strong partnerships waiting for less experienced members to start a table and join them so as to have an afternoon of "bunny bashing". this is one of the biggest bugbears

 

3) you are much less likely to have strong players partner weaker players, that just can't be good for the game

 

4) it is a regular occurance for a strong partnership to sit and wait for over an hour to get any ops. If ratings where to be implemented here i would bet the amount of tables asking for adv+ or exp only tables would drop, people would rather win higher ratings than enjoy competative games

 

So for the above reasons and probably a few i have forgotten i am against any form of ratings

[Rado]

Hi all friends,

First of all thank you Sceptic for your nice words:-)

I may assure you that neither Stanned, nether me think that we are "world class". Maybe we are good players and we love bridge, but "world class" are those who win or near win at the world stage:-)))))))))))))) and we are happy to have in BBO some of the real winners of the top world live bridge events.

Back to the ratings issue:

I was lucky to discover BBO in its early months after creation. I was twice lucky to discover Mr. Fred Gitelman - a great man and top player, devoting his time and efforts to create and maintain a place for playing bridge with a smile. At those early days of BBO with let's say 100 people logged in we have some conversations with Fred and he pointed that BBO is a place for pleasure, not for competition.

 

I've tried, I'm trying and I will try always to help the idea for rating-free, pay-free but SMILE piece of the bridge universe

 

Kind regards

Rado

[mink]

Hi DrTodd,

 

yes, the problem that you are refering to does exist. However, I really doubt that people would not go for higher ratings because nobody else can see them. They would still go for them! They would do it even without any reason, but the way you propose it, there is a reason: with a low rating you have fewer tables where you could possibly join.

 

Currently, if my pickup partner makes stupid mistakes in 3 boards in a row, I just think he might be having a bad day. With a rating system I might think I should really leave now because he ruins my rating. I would not like that people think this way.

 

The only solution to your example problem I can see is you and your partner leave and open another table.

 

Karl

[paulhar]

I can see I've stirred up a hornet's nest here! I'd like to respond to some of the recent postings. First, let me pose a question: The following wouldn't affect me because I couldn't be that rude, but is it better to have a table with a minimum rating, or to not have any ratings and willy-nilly boot any players not deemed by the host to be competent to play at that table? (I've seen tables listed in a way that suggests that this might have happened!)

 

In response to the statement, 'can one not trust his friends'? the answer is clearly NO, since I have a friend from real life who plays a wretched game but I would play with because I like him/her. Someone who marked me as a friend is going to be sorely disappointed to play with this person.

 

In response to the statements, 'nobody would want to play against strong players', and 'and experienced partnership could wait for an hour for a game', I noticed that 'mycult' stated that he likes a game where he's the weakest player. So do I. I'm sure we're not the only two. I don't really care about my own personal rating as much as I care that the people that join my table aren't going to be such that their partners are going to want to leave after one hand. Alternatively, if people are scared, they could start an unrated table with a minimum rating, so that their opponents wouldn't lose points. Besides, if they're that strong, they have a high rating and lower-rated people shouln't lose rating points to them if they play as expected by their own rating! If people don't understand that, they could be educated. An article simple enough to be understand by the non-math minded could be posted about ratings in the articles under 'explore bridge'. Do people read those things? I don't know, but I have. The news window could point them in the right direction the first few days of ratings implementation.

 

In response to the 'kibitzer bots' to check people's ratings, can't you get an idea of someone's rating by simply playing a few hands with/against them? And really, why should anyone care if someone wants to go to all that work to do that? I could care less if anybody knows my rating. I suggested not being able to see other's ratings to elminate people looking down on lower-rated players. Besides, I would rather have someone spend their time on kibitzer bots than on writing a virus to bring down Bridge Base (seems like the same kind of mentality)

 

One common complaint is that nobody wants to play with an overrated partner or against underrated opponents. If you can't see the ratings, how can you tell? You assume someone's rating is commensurate with the way they play.

 

Bunny bashing? I hope that the initial ratings tutorial will explain why that won't work. Firstly, the 'bunnies' will have low ratings if they're truly bad players, so your expected results are pretty good. You have to exceed these excellent results to gain rating points. OK, lets say you CAN exceed these great results. You are now overrated. Being overrated is transitory. As soon as you play in the general pool of players your extra rating points will flow back into the system and your rating will revert to the mean (i.e. YOUR expected rating based on your skill.) If bunny-hopping works, you will have to ALWAYS do it just to MAINTAIN (note, I did not say INCREASE, beacause you can't) your current over-rating! Does an experienced partnership really want to do this all the time just to be overrated when nobody can see the ratings?? Of course, this assumes that you can increase your rating by bunny-hopping, and I'm not convinced that you can. Of course, there is one way to increase your rating - and that is to learn the game! Play more seriously. Read books. Discuss bidding with your favorite partners. The Bridge Base store offers many fine products to help you toward that goal. Pay more attention when you're playing. Not only will it help you, but your future online partners will be happier too.

 

Speaking of serious games - don't you think that ratings will make for more play where people aren't constantly leaving to stir dinner, check their stock quotes, and do whatever else they do which needlessly slows down the game? If people care at all about their rating, wouldn't they play at a rated table when they wanted to focus on bridge? I have a friend who rarely plays online bridge, calling it 'not real bridge' because people frequently don't play an obvious card for several seconds, and it's because they're not at the table. He claims that marking it a 'fast table' dosen't get the desired result because he does not mind if someone takes a long time with a real problem, just like in a real game. Its those unexplainable slowdowns that irk him. "And frankly", he says, "in self defense, I do something else while playing online bridge. I wouldn't do this if everybody else didn't." Don't you think these avoidable delays would be cut down in a rated game?

 

In response to "similar to ATP rankings in tennis" - of course not! The ATP ranking is almost as flawed as a ranking system as the ACBL masterpoint system! I'd be happy to point the reasons if anybody asks but that's off-topic. If Lehman ratings work like chess ratings, and I think they do, they would be so far superior to anything that ATP or the ACBL does. Don't get me started on ladders.

 

I think somebody suggested self-rating your partners and opponents after playing with them. NNNNOOOO!!!! (1) A good American player with little online experience is going to give a fine European player thumbs down for (a) leading low from a doubleton, which must be common practice in some coutnries, (;) passing a free bid in a new suit, which is commonly non-forcing, etc. (2) If you don't like someone, you can log on with many different user names and give them a black mark from each one. (3) If you really want to play with somebody, you give them a black marks so that others WON'T want to play with them. If I thought awhile, I could come up with many more reasons, but do I really need more?

 

Once again, the people who think that strong players won't partner weaker partners need to be educated about the rating system. The weak partner has a low rating because he is weak. The expectation, therefore, of the partnership of those two players, is not anywhere near the expectation for a partnership of two strong players. Of course, the results won't be that good. But they're expected to be not that good! If you don't do even more poorly than the bad expectation, then your rating won't go down. Sure, it won't go up either. If you expect it to go up when you play, you need to be educated again. Your rating should only go up when you exceed your own expectation, which, unless you're constantly improving, will only happen about half the time. The other half, it will go down.

 

Yes, there may be more rudeness by the players that don't understand ratings. In response to the player who said 'my partner just booted three boards, I'd better leave.', if this is your partner's expectation, then his rating is just gawdawful and you're not losing points by staying. On the other hand, if your parnter isn't such a bad player but has just made the worst play of the century, you can be sure he feels a lot worse about it than you do and he's going to dig in and make sure it doesn't happen again. (Provided he's not spending energy deflecting your caustic comments.) Ah, yes! Maybe ratings will DECREASE rudeness! Yes, you're rude, your partner plays worse for it, and YOUR RATING DECREASES and you can't play at tables you should be entitled to play at. Or, my goodness, no - I have to be NICE to my partner to maintain my rating?? No, that can't be possible...., no not just possible but obvious! Certainly, that will be in the tutorial on ratings... Oh, the flip side, somebody asks? I can be rude to my opponents and get a better rating for it? Won't work. Unless you enjoy people leaving your table and waiting ten minutes for someone else to fill in. Perhaps eventually the BBO administrators will catch up to you and boot you from the site. Maybe when you come in with your new username, you'll realize it doesn't work and play nice. However, I've found that most of the venom is directed at partners. Hardly anybody has ever said anything rude to me as an opponent (except once when I forgot to say BRB and I deserved it!) and usually I only say things to an opponent which might be considered bad by some when he maligns his partner (usually incorrectly) and then usually in private as I don't want to make him look bad to the whole table.

 

Those of you that oppose ratings can perhaps help me out. I don't play often enough on BBO to establish set games, but would like to come on and play at a competent table. (I think this might be common among the membership of BBO.) I have clicked many people as friends, but when I log on, those that are on are usually already playing. When I try to click onto a table that looks like it might be competent, I am rejected since according to the BBO guidelines, I am Advanced, not having won any national titles and only a few regional ones, and they are looking only for Experts and World Class players. I presume that at a lot of these tables, I might be the best player at the table (judging from what I see from most people that click themselves as Expert) but cannot bring myself to call myself an Expert. At the tables where I am not rejected, the play is often deplorable (mostly by opponents), which people clicking in and out after almost every hand because they can't stand their partners. If I start a table, the people that click into the table haven't bothered to read the comments. I might say "2/1 partner" and get someone playing the Polish Club. Yeah, I know the solution - I need to learn the Polish Club! There are probably a lot of other people that feel the same way. I would be nice to be able to log on, play a dozen hands or so with the same congenial partner and opponents, all of which can make 3NT with nine top tricks and can trump a loser in dummy if need be. Given the lack of ability to put a minimum rating on a table, I don't see a good solution. Is online bridge not right for me?

Paul Harrington (paulhar@juno.com)

[hotShot]

Hi Paul!

 

Online-Bridge has a very high potential for abuse.

 

If one could only see his/her own rating, players could be asked to send a screenshot to prove their rating ....

 

There are lots of ways to cheat. I don't what to make this a cheaters resource, so i won't give examples here.

 

I ‘m sure you know, that 2 strong players don't necessarily make a good pair. So how do you calculate the strength of a pair.

 

Do you know how a tournament result is calculated? Have you ever thought about “fair movements” ?

 

If you play a BBO tournament with 100 pairs and 5 rounds of 2 boards, you and your partner will have played about 5% of the other pairs. You could have the 5 best pairs as opponents, another pair could have the 5 worst pairs playing. You will have 10 results that are average or worse, the others might get a lot of gifts scoring average or better.

Should their ranking be better than yours ?

 

Creating an offline tournament the TD tries to create a movement that makes you play at least half of the other pairs.

 

To create a serious ranking one would need to play tournaments with lots of rounds with very few people. Handling divisions where people can move up or down.

 

Until that can be done, any numerical ranking system will not be accurate.

 

Have a nice day

hotShot

[badderzboy]

As an 'average' player on BBO, I think ratings would be an unmitigated disaster for two reasons,

(i) People would leave tables with even greater frequency than now to avoid a 'bad' score.

(ii) Snobbish behaviour towards people with low ratings and new players to BBO!

 

Ratings prove only to boost ego's and not good manners / ethics!

 

To cheat the telephone gets round all electronic countermeasures but never done it as I play to enjoy not to win by cheating !!!

 

Steve

[paulhar]

Responding to HotShot's thoughtful post:

 

"Online bridge has a very high potential for abuse".

 

Normal bridge doesn't? It's the nature of the game. I've heard anecdotes about people sitting at table 8 N-S in a tournament so that they could see table 7's from two different sections! And having a minimum rating requirement on a table negates the need for someone to send a screenshot of their rating. There are lots of ways to cheat at any sport or game if one is so inclined. Frankly, I don't see any good reason why one would want to cheat - what's the thrill of winning if cheating was required? I'll admit that this is not a universal opinion and there are those who cheat. Why would they be any more likely to cheat to achieve a rating that nobody else can see? The only reason that comes to mind is that they want to be allowed to play at a table that they don't belong at due to their bridge skills. So, they cheat, they become overrated, join a good table, and it becomes obvious to all that they don't belong there. They get ostracized, which is their due for cheating.

 

While I have thought about the problem of two strong players not necessarily making a strong pair, it would seem pretty onerous to keep track of details necessary to rate pairs, since everybody could potentially have thousands of partnerships from regular to 'click in and play a hand'. There could be a higher expectation given to a pair who has played more deals together. I'll be the first to admit that it would be quite difficult for an online service to determine that my wife and I have played thousands of deals as partners when we've played only a handful online. This is a tough problem - there is proably some partial solution but I can see that this might be the bane of accurate bridge ratings.

 

About the strongest five pairs and the weakest five pairs: Let's look at a chess tournament. My friend and I enter a tournament (on the Swiss System) and I lose the first two games and play patsies and win the next three. My friend wins the first three, with the competition getting tougher each time, but then he is far overmatched in the last two games playing against masters and loses the last two. We have identical 3-2 scores and thus place similarly but when the USCF rating is computed, my friend gets a much higher rating that I do, having scored that 3-2 record against much tougher competition. Each game is taken into account - his expected chance of winning, and the rating of his opponent.

 

Bridge players seem to keep making the mistake of equating 'rating' with 'masterpoints'. They aren't even close. Even forgetting that masterpoints are an attendance award, you could win a club game in East Podunck where the strongest player learned bridge last year and is teaching the rest of the town what she knows, or you could play at a same sized game in a strong field. Winning either will give you the same number of masterpoints. And of course, there's events restricted by things having nothing to do with bridge ability. Others mention ATP rankings, also moderately an attendance award. However, somebody does as well by beating some schlepp who beat Andy Roddick as by beating Andy Roddick. With a chesslike rating structure, that wouldn't be true. Your rating is based on your actual opponents and whether you beat the expected results based on your rating and your opponent's rating.

 

The same should be true for tournaments and rated tables. It would be conceivable to win the tournament and lose rating points - if you and partner were highly rated and happened to draw five novice pairs as opponents and didn't trounce them as badly as expected by the difference in rating. The other poor pair who played the five strongest pairs in the field would have their ratings adjusted based on how they did compared to how they would be expected to do versus those five strong pairs. Forget the masterpoint mentality! Ratings should be entirely based on expected results against your current opponents. (A really awesome rating system would also take into account the ratings of the N/S pairs you competed against as opposed to the E/W pairs that they competed against - but that would probably only significantly matter in a team game with one other team. When the board is played 16 times, this effect is negligable.)

 

The current tournament format may be unfair as to determining who wins the tournament, but shouldn't be unfair in calculating ratings. A cool way of fixing the unfair tournament format would to pair each round (trivial for a computer) using the Swiss system - pairing the leading pair against #2, #3 vs #4, etc. Also good because eventually you play pairs at your own level. The downside to Swiss parings: With the current pairings, anybody can win. Everybody knows that and the top players who care can go find 8 of themselves and play a team game and eschew the tournament. But it might be good for online bridge that anybody can win. So, while it's not FAIR, it might be best. Does anybody really care that they can be beaten by inferior pairs? Judging by the number of entries in the Total Points tourneys, not many do care. These tournaments are a lark - they're pure entertainment - and there's nothing wrong with that. But they can be rated a lot more fairly than you give credit. I would assume that most of the rated deals would occur in the Main Bridge Club rather than in the tournaments.

 

With all the great minds we have playing on/contributing to BBO, I have no doubt that the logistics of a fair rating system could be worked out. If there is a strong consensus that it would increase cheating and boorish behavior, I'd be quite willing to jump to the other side and figure out some other way to avoid the problems I've mentioned on earlier posts. I just can't see how cheating would be increased to attain a rating that only the user can see. Are there really masochists out there who want to play at a table where they're not wanted when they can just as easliy find a table where they would be welcome? Maybe it's just me - but I'd like to play at a table where the other three participants are happy that I'm there.

 

By the way, if anyone wants to devise fair ratings and/or fair movements, I've done a fair amount of work on both and I'd be happy to share ideas. paulhar@juno.com

[hrothgar]

Hi Paul

 

I think that I agree with your basic premise: A rating system that was completely private probably would not encourage cheating.

 

With this said and done: I spent a fair amount of time trying to come up with different types of rating systems. I eventually concluded that it is not possible to develop a rating scheme that

 

(a) Can accurately rank pairs (or players)

(:blink: Can be understood by average players

 

I have come to believe that the hassle of administering the a system and explaining to end users why their ratings are, indeed, accurate far outweight any perceived benefits of implementing a system.

[sceptic]

Just a quick idea for a ratings system, based on two ratings.

 

Learner, has not quite mastered the triple flip flop, restrictive choice multiple squeeze

 

Arroagnt so and so who knows everything

 

or just make friends and judge people as you find them, mark them as friend and insert comments, i.e. potential partners or decent opponents, good fun player, etc, anyone you dont like you can mark as an enemy.

 

Anyone that comes up with a site that good probably does not need a rating system.

 

Alternatively design a bridgeplaying site yourself, make it free and see if you can create and administer a rating system

 

Good luck with the later, I kinda like the rating system, but then I dont think I suffer from delusions of grandeur, nor do I have an over inflated opinion of my own abilities, nor am I so elietist that I want to pronounce to all how good or bad I am, play bridge with me cos you enjoy bridge or my company, either is good for me

[paulhar]

Reply to brothgar:

 

(1) Do people understand the USCF rating system? They still happily play and 'believe' the ratings which appear to go up when they play well and go down when they play badly.

 

(2) Is it that hard really? Four people come to a table with ratings that approximately reflect how well they play. The N/S pair's two ratings are added together, as are the E/W pair's ratings, and the difference taken. This difference can predict the expected number of IMP's or matchpoints that should be won per board by the stronger pair. (In a 2-table team game, you must total the whole team.) On each board, the pair that exceeds their expected result gains rating points derived by some tiny percentage of the excess, while the other pair loses the same. (Examples can be given.) Is this really so hard to understand?

 

Of course, some adjustments might have to be made to counteract the deflation of ratings due to players improving, and perhaps for regular partnerships, but these are minor indeed and need not be explained to make things work.

 

 

Reply to sceptic:

 

Count me as a 'learner'! Everytime I play is a learning experience. Do I want to prove to others how 'good' I am? Not at all - I know how bad I am! Besides, what I'm proposing, with hidden ratings, the showoffs can't even haughtily show their ratings. (I would even support ratings that not even the user can see - but is allowed to start a table defined by his unseen rating, such as 10 below me to 10 above me.) The reason I'm supporting ratings (an unpopular view, it seems) is that when I play, what it is I'd like to learn to play better bridge against competent players, rather than (1) how to take advantage of players that probably would be happier playing with players at their own level, or (2) how to avoid the unpleasantness that goes with a various string of partners coming in and playing with a weak opponent for a hand and leaving, sometimes with a caustic comment about the player's choice of level.

 

Reply to badderzboy:

 

As pointed out in an earlier post, someone shouldn't leave a table with a bad partner simply to avoid having their rating demolished, because the partner probably also comes with a bad rating, which means bad results are expected, and anything acheived higher than expectation will increase your rating. It might teach people to be nice to their bad partners - as they will play better that way. Can you imagine - a way to boost your rating is to go play with bad players, and make them feel good about themselves so they play above their normal game?

 

As for the snobbish behavior toward people with bad ratings or people new to BBO - how in heck would they know? Your rating is known only to you (or perhaps not even that.)

 

Actually, I'd like to propose a poll. Please do not answer if you don't have experience playing on rated sites. If a predominate number of replies state that badderzboy is right about ratings promoting bad manners, then I'll admit that all my writing about ratings was a big mistake. Of course, the poll will have a huge bias against my position since I think I would get a lot more support if I polled the entire online bridge playing community rather than BBO members, some of which seemed to have left other (perhaps rated) sites in a huff because they found people unfriendly. Frankly, my online experience is: BBO, the MSN Gaming Zone, and Stepbridge (the only rated one of the three), and found the Stepbridge players to be the friendliest of the bunch. I have encountered a higher percentage of rude players here and on the Zone. Most of the rudeness was not directed at me (happily admitting my errors usually deflects rudeness), but it is unpleasant just the same.

 

Anyway - the poll is as follows:

In your experience, do the players on rated sites have worse manners than those on non-rated sites?

 

I look forward to seeing the results and will happily report the findings no matter what they are.

[DrTodd13]

Hmm...lots of comments here. People are cheating now in tournaments and at regular tables. Why are they doing this? There doesn't seem to be a reason to me but people are doing it. So, the question is how much worse would this get if there were a ratings system that only a player could see.

 

I dismiss statements like people will be asked to send screenshots to prove their ratings. How many people would even know how to do this? Of those that do, how many would actually bother? Just don't play with people who would make such a silly request.

 

With respect to a kibitzer bot(s) that go around and create ratings and store them external to BBO, nothing is stopping this from happening now. I'm not sure that knowing one person's rating makes this process any easier or better.

 

Somebody also said that all we have to do is to educate people that the ratings system works so that they wouldn't be afraid to play with players of much lower ability. Well, OKB has a ratings system and they have tried to educate people that their system works and accounts for these sorts of issues. Does anybody believe it? I would say very few. It seems like once a rating exists it gets propelled into the public eye. I think some were suggesting that you could limit tables to those above a certain ratings even though you wouldn't be able to see their rating. This sort of creep to public ratings I wouldn't like. The self-rating would still be useful for that purpose.

[hotShot]

Hi Paul!

 

In a chess match one of the playes is the winner and one is the looser.

 

In a bridge tournament you do not compeat with the opponent you play, but with the other pairs/players playing the board from the same side.

 

Your opponents result is compared to all pairs that played the board his direction.

 

So when you leave, there is no winner and looser, that is why the chess rating can not simply be used for bridge.

 

Forthemore some hands are simply not selective.

 

If you have some sort of ranking you might predict if a pair will perform better than another in a tourney, but to expect some sort of IMP-difference per board you can predict is not the way bridge works.

 

I'm thinking and experimenting with a rating algorithm for some time now and it's not that simple.

 

Have a nice day

Robert

[paulhar]

Hi Robert!

I didn't see an E-mail for you - it appears you've worked on the problem so I'd like to discuss it with you. I'll start with this post. The discussion of bridge ratings may be moot as far as BBO is concerned, based on the early results of the poll. However, I think it's an interesting exercise in and of itself. So, here goes...

 

The date: June 2160. Bridge is a professional sport. The finals are between the heavily favored New York BridgeYanks (boo!) and the underdog upstart Florida Marlintrumps (yay!) Both are 4-man teams. The oddsmakers in Vegas are gleeful as they have set the odds well to get equal money bet on both sides. They have made the Yanks a prohibitive 180 IMP favorite in the 120 board final. The happy Marlin bettors are rooting for a flattish set of boards so that their teams lose by less than 180. But in any event, the smart money doesn't see any advantage to either side, figuring that 1.5 IMPs per board is a reasonable expectation.

 

How was that figure derived? Simply by comapring the ratings! Yeah, it's not that simple. Or is it?

 

The Yanks' pair A, based on results earned in the past based on common opponents, is, let's say 0.6 IMPs better than Marlin pair C, and 1.1 IMPs better than Marlin's pair D. The Yank's pair B, based on results in the past based on common opponents, is, let's say 0.4 IMPs better than Marlin pair C, and 0.9 IMPs better than Marlin pair D. Another way of saying this, is that if Pair A were to play neutral pair E in a cross-IMP event, they would expect to do 0.6 IMPs per board better due to ability than pair C would. (Logically, in the above example, they would also do 0.2 IMPs per board better than their teammates, but that's irrelavent.) OK, so if A (N/S) plays against C and D (N/S) plays against B, then you COULD say that A has a 1.1 IMP advantage per board against their counterparts playing the same direction (D), and B has an 0.4 IMP advantage per board vs their E/W counterparts ©. So, the team has a 1.5 IMP advantage per board. Surely this won't be true on every board, a flat board will probably be 0 IMPS, whereas a touch-and-go game might be a larger advantage to the stronger Yanks. But the EXPECTED advantage is 1.5 IMPs per board. Or, alternatively, you could talk about A's 0.9 IMP advantage at THEIR TABLE and B's 0.6 IMP advantage AT THEIR TABLE and come up with the same result. When pairs C and D switch places, the advantages are the same, but the numbers in the above explanation would just switch around.

 

If these pairs were rated, and the Marlins beat the spread (lost by less than 180), their rating should improve a little, while the Yanks' should decline. If the Yanks win by more than 180 for the match, then their ratings would go up and they should be even more favored next time.

 

Just as the oddsmakers can handicap a match between the BridgeYanks and the Marlintrumps, certainly there must be some number that you can put on an expectation in a team match consisting of any two pairs against any other two pairs.

 

Going one step further, isn't crossIMPS just an average of 15 team matches - all 15 being your pair against your table opponents, each of them with one E/W pair as teammates (if you're N/S) and them having a N/S pair as teammates. Each of those 15 mini-matches has an expectation of IMPs advantage to you (possibly negative.) With any kind of decent ratings, this expected advantage would come from taking your advantage over each of your N/S counterparts and taking each of your opponent's E/W counterparts' advantage over your opponents to come up with an expected IMP advantage for that mini-team. (Yeah, I know your teammates are changing every hand! That's immaterial, they're recalculated each time. Computers are fast!) So, you have an expected IMP gain/loss on this board based largely on the difference between your rating and your direct opponents' rating, which will count 15 times, but also on the other competitors you're being teamed up with and against. Beat that expected gain/loss, and your rating goes up some tiny amount. Underperform expectation, and it goes down.

 

Does it work on every single hand? Of course not! Sometimes you get lucky and are a little bit overrated for a while. But being overrated is transitory, it makes your expectation higher than it should be, and thus less likely to meet, so your rating should revert back to its correct level. Underrated players should correct for the same reason; their lowered expectations should be easy to beat. On average, nobody should be underrated or overrated for long.

[helene_t]

At the Dutch site StepBridge, you get compensation for playing with a weak partner and/or against strong opponents. In theory, it should solve the problem with strong players refusing to play with weak players, or strong players earning cheap IMPs against weak players. But how to calculate that compensation? You can probably immagine that the threads on that issue have attracted 1000+ postings.

 

I think that if some tournament director wants to implement his own idea of a rating scheme for his regular participants, he can have his way. If it becomes popular, other TDs will adopt the same system. But please don't impose some standard rating scheme on all tournaments. We will never be able to agree on how such a rating scheme should work, and most will probably be better off without ratings.

[Free]

When stepbridge was free, I also played there, and I remember that rating system! Unless it changed, it sucks (sry to say). This is how it works if I remember correctly:

 

- there are 9 level: 1 is absolute beginner, 9 is the best

- after every 30 hands or so, you ranking is recalculated, based on these hands. You can go up or down 1 level, according to the scores SB gives you.

- when you play against other pairs, the levels of both pairs are summed up, and their relation gives a value to some parameter to calculate your scores. This adjusts the %-score for the experts and for the beginners, since the beginners have a very big change to get 0% on hands this way. Now they'll get at least some %. Experts make tops a lot more against beginners, so they won't get the full 100%.

 

As you can see, this system gets quite discriminating, since good players won't play against beginners anymore, because they'll lose their great level-9 status. If they happen to get to play new members which play very good, they get negative %'s sometimes!! The sollution a friend of mine found was to use several logins: he had 1 with level 9, 1 with level 6-7, 1 with level 4-5 and 1 with level 1-2, and keep these logins at that level (playing bad was obligated sometimes :D ). This way he could almost always play somewhere he wanted. When I started I couldn't play a decent game, since playing against a level-1 loses too much points! Most tables required level 4-6.

 

Also, beginners will stay beginners, since they won't learn much playing against other beginners. Giving players a ranking is pure psychological, and gives a negative factor! Some people will do everything to get the highest ranking, others will do everything to keep their ranking,... Imo, a non-hidden ranking system would give a very negative factor on this community. And I don't know what you could accomplish with a hidden ranking (players don't know they have a rank).

[guggie]

So when you want to improve yr rating you choose a p who can play but is a little low in rating by accident , and choose opponents who cannot play but have a high rating.

It is boring bridge, like taking candy from a baby.

I DETEST RATING

 

Please please lets continue to play for love of the game

 

(I also hate writing in capitals colours bold and with exclamation marks, but i DO feel strongly about this. I felt so happy discovering a site without rating and now it is starting on BBO too

[Chamaco]

My personal opininion is that the benefits of ading a rating system would be minimal.

 

1) right now, after a while you play on BBO, you get to know which players you like and which not.

 

2) yes, sometimes there is no known partner available, so you have to "guess" or their self-statement. Guessing on a BBO point rating would be more reliable, but by how much ?

I don't know how well the rating systems of the foreign federations work, but speaking of the ratings in Italy, I can tell you they are absolutely meaningless.

You will find MANY MANY players with a low ranking which are actualy MUCH better than other players with SIGNIFICANTLY higher rank.

And this is not an exception, but an extremely common occurrence.

 

3) on the other hand, my experience in any field that adopts rating systems is that people become les nice. One does not need to be a genius to recognize this in bridge clubs and bridge competitions, and my long experience as a ches player confirms that it holds true also for chess (and other posters will probably have experienced the same in many other fields).

 

4) one of the effects of rating introduction is also that it becomes harder and harder for bginners to play with and against good players. More and more tables become composed of beginners/low level intermediates only.

This is a damage even for the selfish people who want to play only between experts: remember, the bridge world is alive because there are a large number of players, the more players we have, the better it is for everybody.

And the best way to do it, is to let these beginers improve by keeping them in contact with stronger players.

 

 

So why should we introduce a rating system for a minimal benefit (knowing "better" the strength of your pard, based anyway on unreliable criteria), for a probable cost much worse (losing much of the frienly atmosphere and segregating low level players to a level where they can much less frequently interact and improve) ?

 

My bottomline is: let's leave the hierarchies to the bridge federations, and keep BBO as it is.

We do not need yet another means to pump up our ego (which the rating essentially is).

[helene_t]

guggie: I don't think you need to fear that rating is being introduced here, most people seem to be against it. Btw, you probably remember last christmas, when we played for nuts and pieces of chocolate, and nobody knew what the exchange rate between nuts and chocolate was, and besides most of the wine and cheese was given to the winners of the lottery rather than the winners of the tournament, and it was robber bridge which few people can take serious anyway. It was one of the most enjoyable bridge tournaments I've ever participated in. So the least evil rating system might be one which can't be taken serious by anyone.

 

Free: 90% of the members think that the Dutch system sucks. Of those, 90% only think so because they can't figure out what consequences it has and doesn't have, which is, indeed, a complicated issue. I could tell you that since I'm a mathematician, I belong to those 10% who actually know why it sucks. However, the probability that I'm telling you the truth is no more than 10%, in that case. Actually, I have no idea if it sucks more than any other rating system would.

[Free]

It's quite obvious what the consequences are imo: good player's rankings are too low, bad player's rankings are too high. You get a curve which is very high in the middle, and low on both extremes. Also beginners can become experts by bashing even bigger beginners...

 

But the big issue is what happens with the players, how they play, against and with who,... and this had a lot of negative influence! That negative influence is just a proof the rating system sucks imo :D

[paulhar]

OK, looks like I was just plain WRONG! Apparently my experiences with a rated site were most unusual - in the poll, only one other vote for equal manners between rated and unrated sites/tables and that was 'everybody is rude!'. About 90% of you stated that your experience showed that rated tables increased boorishness and/or unethical behavior. (The undisclosed agreements argument was something I hadn't thought of.) And if that's really true, I don't want ratings either.

 

By the way, I feel like I understand the Step rating system also, and agree with Helene's assessment of its merits :D I did a simulation once and wondered what would happen using the Step system without a top level of 9. After many hands, everybody's ratings went up, and eventually even the most pathetic players would levatate from their '1' rating, being pulled up by the massive ratings earned by others. The skew came from the fact that 3% above average raised your rating but 5% below lowered it, so there's an automatic upward bias for attendance. The same was true for IMPs but I don't remember what the exact IMP totals needed for advancement/demotion were.

[DrTodd13]

Just a couple of requirements on any ratings system that would be developed. First off, somebody should not be given a rating unless the number of their partners and opponents is sufficiently connected to the larger BBO membership. For example, if Meckwell played on BBO but they only played against some other world class pair but not as good as them then if analyzed in isolation then Meckwell would be above average and the other world class pair would be below average. So, there has to be a certain amount of intermixing of partners and opponents for a rating system to have any meaning. Does BBO currently have enough such intermixing for the average player? I don't know but I do know there probably are people who play set games with few enough partner's and opponents that a rating for them wouldn't make any sense.

 

If a ratings system were to be any good then it has to be predictive. One of the big failings of the lehman system I think is that it tried to compute how well a 54/61 pair would do against a 47/52 pair. Moreover, the lehman system treated a 55/55 pair the same as a 50/60 pair which is obviously not try. A pair (except for declarer play) is limited in general by its weakest member. Rather than trying to create another formula (which is pure guess work), I think the right approach is to have a 4-dimensional matrix where each dimension represents the ability of one of the people at the table. This matrix is initialized at week 1 with some guess as to what the result should be but each entry in the matrix is itself a weighted moving average so after each board (or possibly once a week/day) that entry itself is updated to reflect the actual score seen. So, if a 50/60-55/55 matrix entry is initially 0.0 and the 55/55 pair win 5 IMPs on a board then the 55/55 pair will move up slightly to 55.2/55.2 the 50/60 pair move down slightly to 49.8/59.8 and the matrix entry moves up slightly to 0.2. Then we'd have to deal with issues like fractional ratings and how to look those up in the matrix. Moreover, they may be specific ratings combinations that are rarely seen in actual play and so those matrix entries would be updated very slowly. Holding 3 dimensions constant and varying the 4th dimension, the result should be at least be smooth and not-chaotic so to some degree you could change adjacent matrix entries to maintain this property.

[hrothgar]

couple quick comments here

(my Internet access is very limited these days)

 

Back when I was trying to develop a ratings structure at OKB, I reached a couple significant conclusions:

 

#1. Start with the easy stuff.

Work on developing a rating system that can accurately rate PAIRS.

If/When you can evaluate the performance of a pair, you can try to

decompose this into rankings for individual players.

 

#2. Use signal processing models.

Most of the work on rating systems was based on statistical methods such

as regression analysis. from what I can tell, signal processing is a much

more fruitful avenue for exploration. Discrete Time Kalman Filters look

particularly appropriate.

[luis]

Since this topic is active I will re-insert my idea about rankings here:

Bridge is a pairs game, so instead of having a ranking for each player keep a ranking for each pair.

An individual will then have different rankings with every different partner.

In this way you can see how good your opps are as a pair or how good or bad you are doing with some partner.

 

Doesn't it make more sense?

 

Luis