[DrTodd13]

I've never understood this mentality. "Self-ratings are meaningless...but we should keep them because they are better than nothing." If they are completely meaningless then wouldn't having nothing at all be better than something wrong most of the time. I don't know about your experience. You may just like to play and the quality of play may not matter much to you. For me, trying to find a quality pick-up game is nearly impossible. I much more seldom play in pick-up games for this reason. Through pain and references from others I have a small set of people that I know that are good enough to play with and I have to restrict myself to this set. In essence, people are already ratings others and to a lesser degree sharing those opinions with others. This system is very inefficient. If you integrated it with BBO then it would become much more efficient. If you don't care what people think of you then why would you care if people were rating you. If such a ratings system helped people find you that you could have an enjoyable game with then why complain?

People complain about the effects of the lehman system and its accuracy but surely its accuracy is far better than self-ratings. Lehman's did have some predictive value for me when I was on OKB. People would get angry on OKB about a bad result and then leave the table. I don't find this situation to be particularly better on BBO. At a main bridge club table, what is the average number of hands that you have the same four people at the table? I don't know but my perception is that it is less than 5. Lehman's may generate table churn but BBO has plenty of table churn as well and much of that is due to bad results just like it was on OKB.

[Al_U_Card]

The table churn is aproximately equivalent to the stomach churn induced by some of the play exhibited...... That being said, my rating system is to play with advanced or expert (self-rated) players and then add them to my friends list. They may be better or worse than I am on a given day, but if our methods are compatible and they are pleasant, reasonable people I would play with them at any opportunity.

[Brandal]

DrTodd13, on Feb 24 2006, 02:28 PM, said:

I've never understood this mentality. "Self-ratings are meaningless...but we should keep them because they are better than nothing." If they are completely meaningless then wouldn't having nothing at all be better than something wrong most of the time. I don't know about your experience. You may just like to play and the quality of play may not matter much to you. For me, trying to find a quality pick-up game is nearly impossible. I much more seldom play in pick-up games for this reason. Through pain and references from others I have a small set of people that I know that are good enough to play with and I have to restrict myself to this set. In essence, people are already ratings others and to a lesser degree sharing those opinions with others. This system is very inefficient. If you integrated it with BBO then it would become much more efficient. If you don't care what people think of you then why would you care if people were rating you. If such a ratings system helped people find you that you could have an enjoyable game with then why complain?

People complain about the effects of the lehman system and its accuracy but surely its accuracy is far better than self-ratings. Lehman's did have some predictive value for me when I was on OKB. People would get angry on OKB about a bad result and then leave the table. I don't find this situation to be particularly better on BBO. At a main bridge club table, what is the average number of hands that you have the same four people at the table? I don't know but my perception is that it is less than 5. Lehman's may generate table churn but BBO has plenty of table churn as well and much of that is due to bad results just like it was on OKB.

Not sure if you replied to me but....

1. I wasn't complaining about anything,merely expressing
my opinion. If Fred & Co decides some rating scheme,that
will also be ok with me,I just happen to like the friendly
approach he has chosen up to now,once skill level based
on what others think,or based on scores or placements are
implemented,BBO will become a less friendly place for many players.

This is ofcourse,only my opinion.

2. How does any rating scheme tell you "this is the partner
i've been looking for" without playing with him and judge for yourself?

I also have a "small set of people" I play with,most of the time.

3. I never said I don't care what people think of me,I said it's
not important to me regarding having a committee deciding my skill.
Again,I was not complaining,unless having a different opinion is complaining.

I have no doubt this Lehmann system is more accurate than selfratings,
it's not the accuracy I am concerned about,it is the "side effects".

I wouldn't want players who look at ratings to find me

Now,that could mean I have no ambitions,could mean I'm a terrible
player too,could mean that bridge isn't all that important to me,
we all have different levels of what bridge is to us.

So....bottom line is I wouldn't have a problem with others rating me,
or some other type of rating,it just isn't important to me,and I try
to stay away from players who think it is.

Having said that,maybe players could choose how to be rated,or
not being rated.

I have played 1-one-ACBL tourney on BBO,and got a 2 next to my
name,I wish it would go away soon. embarrassing.

[ArcLight]

Somewhere is posted what is meant by Advanced, Expert, etc. I think Experts are supposed to have won a national title, Advanced is a strong club player who wins sectionals and maybe regionals. Intermedaite is a decent club player.
Probably many people are not aware of this.

How easy is it to rate players based on their defensive play, if they don't have time to discuss things? Also, if an expert was paired with a terrible player, I think the experts defense would suffer as he is fooled by his pards random carding. He would be rated a bad player.


Ho does the Lehman rating work?

How would a players rating be affected is they improve over time?

The value of ratings is to be able to play with players at your level. Its no fun to play with and against much weaker players. (Though I'd be happy to play against stronger players if they would let me)

[awm]

Lehman rating works sort of like a chess rating. You have some score between 25 and 75 (starting at 50, which is supposed to be average). Your projected match point result against a pair is computed: Sum of you and partner's Lehmans, divided by sum of all lehmans at the table. So a pair of two 50s playing against two 60s are expected to get about 45% of the matchpoints. If you do better than this, your lehmans go up. If you do worse they go down.

The main problem with accuracy of the lehman system is that it doesn't take partnerships into account. Two "average" players who have played together for years tend to do a lot better than two "average" players who have never played a hand as a partnership. It also doesn't really adjust properly when partners have very different skill levels (for example teachers playing with students).

There are some social issues with the lehman system too; you can probably rate a player with lehman rating around 40 or below as not very good, and around 60 and above as pretty good, but beyond this it's not all that accurate. However, on OKB people frequently were unwilling to play with anyone not within 2-3 points of their own lehman score, even though it's quite clear that lehmans are not accurate to this degree of precision. The rating system also discouraged pairings of good players with bad players (because the good players didn't want to hurt their lehman score).

[hotShot]

I don't think Lehmann rating properly adjusts for the strength of the field. Even in a world class field, some pairs have to end up below 50% and getting 75% in a beginer tourney will not make you a good player.

[awm]

hotShot, on Feb 27 2006, 09:23 AM, said:

I don't think Lehmann rating properly adjusts for the strength of the field. Even in a world class field, some pairs have to end up below 50% and getting 75% in a beginer tourney will not make you a good player.

This isn't really the problem. If you do badly against highly rated players, it won't hurt your lehman total much. Similarly if you win against poorly rated players. It's true that computing lehmans based on one tournament won't be too accurate, but over the course of thousands of boards these things tend to average out.

Chess ratings are computed similarly, and are quite accurate. The only real "problem" that seems to arise is when a group plays a lot amongst themselves and very little in a wider field. This tends to create a situation where members of this group have ratings not necessarily correct relative to everyone elses (i.e. the group average will be around 50 lehman even if the members of the group are in general much better or worse than global average). However, online bridge seems to have enough cross-over that this will not occur.

Really the main issue is that bridge is a partnership game, and any rating system that's really designed for individuals based only on partnership performance can't be too accurate.

[DrTodd13]

One problem I had with the Lehman system is its linearity. The lehman system would say that a 60/30 partnership should do the same as a 45/45 partnership. Moreover, will two 60s really beat two 55s by the same amount that two 55s should beat two 50s?

I'll stress again that when we talk about ratings systems, we have to ask what the purpose of such a system is. Is the purpose: A) to give players an indication of how good they are, to give players an indication of how good other pairs are, C) to find new players with which we may be compatible. B would only be useful for the pair itself to monitor its own performance or for others to find potential pairs to play against. As such, I don't think many people would benefit from B. Nobody has yet to propose a system to accurately capture A. To a degree people are right when they say that you can't measure individual performance, only pair performance. So, the lehman system has two problems. 1) Its stated purpose was for people to monitor their own performance when individual performance is really impossible to measure and 2) that they were used for purpose C) when that was not their intent. We know that such a use is inevitable but the system was not designed to be useful for C, only for A. On a side note, why make the ratings visible to others if they were only intended for personal consumption.

Anyway, I'll toot my own idea some more. I think people primarily want a system that would let them know whether a pick-up game is going to be enjoyable or not. Once pairs are established then they will be able to track their progress on their own. What is needed is a way to bring compatible people together to form partnerships in a more efficient way. A lehman-style system is not going to give you this information because partly personality is part of the equation. I'm not sure an "amiability" factor is the perfect way to express this but its better than nothing. If there were much more system information in your profile then BBO could do something like search for people waiting to play who are most compatible in terms of system options (and maybe automatically create a CC with the intersection of both people's profiles) and overall ability. When I say ability, I mean ability as judged by others because when forming a new partnership, an external opinion is all that is important.

[pigpenz]

almost any form of rating is flawed!
I was flabbergasted to find out that alot of the people who play in acbl games that have ratings of KQJ have never played in a LIVE acbl event, in other words all of their acbl masterpoints are from BBO....ouch! NOw there is a flawed system

[DJNeill]

Hi pigpenz,

It's true, the ratings of KQJ are based on masterpoints (not even just ACBL, mind you, but any points awarded on BBO - for instance you could earn 90% ACBL points and 10% other organization points and the sum would comprise how many points are considered when getting a AKQJ...65432). But those ACBL component masterpoints count towards ACBL titles to some degree (ACBL limits how many can be used towards titles). Maybe the online game, with the ease of cheating, should not be allowed to count for real life titles.

Further, both the AKQ... and LM titles are based on achievement, not skill level. Wait, let me use italics: achievement, not skill level. That's more emphatic.

Lots of problems, to be sure. I don't think that we should bash achievement-based things too much. It's a separate issue from where we should have rating systems or not that measure skill - and which those should be. I would think that without so corrupt and inaccurate a rating system as ACBL points, the game would have died out much earlier than it will.

Thanks,
Dan

[pigpenz]

I understand what you mean, i was just stating that i was suprised how many people who have those symbols when I have chatted with them say they have never played in a real live acbl event.... in most of the cases the players are people who have KQ's by their name.

The acbl does have a seperate listing for online masterpoints which only count for moving up in your total but are not included in counts for unit, district, and top 500 races.

Now the AKQJ ratings apply to all pts won in $$$ events on BBO, but people who play in free tourneys have no way to gain pts, but maybe they should? Then the sysmbols would have meanings for everyone who plays on BBO.

[Sigi_BC84]

DrTodd13, on Feb 27 2006, 10:18 PM, said:

So, the lehman system has two problems.  1) Its stated purpose was for people to monitor their own performance when individual performance is really impossible to measure and 2) that they were used for purpose C)

Since it has by now been suggested several times on this thread that the Lehmann system was designed to measure individual performance, I want to quote one of Lehmann's articles where he explains the system:

from Bradley Lehmann's article said:

Some players further treat the reported rating as a rough predictive indicator of an unknown player's OKbridge skills. That is, they use it to guess what level of competence in bidding or play to expect from that person as opponent or partner, when planning their own strategy at the table. Such an interpretation (at one's own risk) is not a direct measurement of the system, although there may be some general correlation between a level of skill and a numeric rating. Keep in mind that the system is designed more to measure you against your own earlier performance than to measure it against someone else's.

(http://www-personal....l/oksimple.html)

I'll leave that uncommented because the article really explains it quite well already.

--Sigi

[Sigi_BC84]

DrTodd13, on Feb 27 2006, 10:18 PM, said:

Anyway, I'll toot my own idea some more. I think people primarily want a

I really like your concept, it seems very well thought through to me. I'm surprised that you didn't get more support so far.

I also found the "prisoner's dillemma" idea from earlier on (page 5 or so on this thread) highly intriguing. This might actually work. Maybe one could combine this with your approach, Todd, what do you think?

Actually I'd really like to see something like this implemented, just to see how well it works. We won't find out if we don't give it a shot!

--Sigi

[AceOfHeart]

ArcLight, on Feb 26 2006, 12:02 AM, said:

Somewhere is posted what is meant by Advanced, Expert, etc. I think Experts are supposed to have won a national title, Advanced is a strong club player who wins sectionals and maybe regionals. Intermedaite is a decent club player.
Probably many people are not aware of this.

bring down the displayed skill lvl by one or 2 notches for about 90% of the bbo players and it should be fairly accurate.

As i said b4 there need to be a prominent display of how the self rating meant rather than being inside an obscure document called "rules of this site" that i think 99.5% of players in bbo never bothered to read

[Brandal]

Sigi_BC84, on Feb 28 2006, 06:43 PM, said:

I really like your concept, it seems very well thought through to me. I'm surprised that you didn't get more support so far.

I also found the "prisoner's dillemma" idea from earlier on (page 5 or so on this thread) highly intriguing. This might actually work. Maybe one could combine this with your approach, Todd, what do you think?

Actually I'd really like to see something like this implemented, just to see how well it works. We won't find out if we don't give it a shot!

--Sigi

Hi

This isn't aimed at anyone in particular,just a couple of questions
in a general manner....

First,let me say I use the "Private" skill rating,because I don't
feel very "comfortable" in any of the other levels.
My "regular" partners know what to expect from me,so in that
sense there is no problem.

I readily admit I'm kind of a minority here,because I fail to
see how others can benefit from what someone else again
rated me as,skillwise.

I asked this before in this thread:

Won't you have to play with "me" and judge for yourself in
any rating system?

What is the purpose of it,just to have a different scheme,let's
try it out?

Wouldn't the average imp score over the last 30 played tournaments
or so give the same indication of accuracy,and the same dilemmas
whether how to "trust" that kind of measurement?

Do we rate opps?

I don't think I want to do that,I just want to play against them.



Again,I really don't object to the fact there might be better ways
to set skill level,or to implement them,but I do worry about the
effects it might have....

[Brandal]

Winstonm, on Dec 31 2005, 11:24 AM, said:

few want to term themselves beginner, novice, intermediate,

Winston

Imagine how they would feel if everyone else rated
them as such......and not themselves.

I mean,it does open up a whole new set of "feelings"....
most players have some bridge-pride in what they do,
at any level

[Sigi_BC84]

Brandal, on Mar 1 2006, 01:11 PM, said:

Winstonm, on Dec 31 2005, 11:24 AM, said:

few want to term themselves beginner, novice, intermediate,

Winston

Imagine how they would feel if everyone else rated
them as such......and not themselves.

I mean,it does open up a whole new set of "feelings"....
most players have some bridge-pride in what they do,
at any level

The nice part of the prisoner's dillemma approach is that you would not be rating your peers on an absolute scale, but compare them to your own skills instead (better, equal, worse). Your pick would not be displayed to the other person, it would only be used to recalculate the new rating for both players.

This will provide a global peer rating of some sort without the problem that you could blame anyone of your former partners for giving you a bad rating.

Maybe it would merely turn out to be a major failure, but I'd really like to try it out. Todd has put a bit more thought into his own ideas, and maybe one could combine it with the above (NB it wasn't my idea but somebody else's in this thread).

--Sigi

[Brandal]

Sigi_BC84, on Mar 1 2006, 10:52 AM, said:

Brandal, on Mar 1 2006, 01:11 PM, said:

Winstonm, on Dec 31 2005, 11:24 AM, said:

few want to term themselves beginner, novice, intermediate,

Winston

Imagine how they would feel if everyone else rated
them as such......and not themselves.

I mean,it does open up a whole new set of "feelings"....
most players have some bridge-pride in what they do,
at any level

The nice part of the prisoner's dillemma approach is that you would not be rating your peers on an absolute scale, but compare them to your own skills instead (better, equal, worse). Your pick would not be displayed to the other person, it would only be used to recalculate the new rating for both players.

This will provide a global peer rating of some sort without the problem that you could blame anyone of your former partners for giving you a bad rating.

Maybe it would merely turn out to be a major failure, but I'd really like to try it out. Todd has put a bit more thought into his own ideas, and maybe one could combine it with the above (NB it wasn't my idea but somebody else's in this thread).

--Sigi

We agree that this scheme,or any other scheme,
has a purpose?

The purpose only,to be able to pick a partner
with better accuracy without playing with him first?

Or a pickup game with reasonable chance of finding
one just by looking at the player level?

Hope the "vote-button" doesn't enable until we have
played at least 20 boards with/against other players.

And I'm still against it

[Sigi_BC84]

Brandal, on Mar 1 2006, 06:48 PM, said:

We agree that this scheme,or any other scheme,
has a purpose?

The purpose only,to be able to pick a partner
with better accuracy without playing with him first?

Or a pickup game with reasonable chance of finding
one just by looking at the player level?

Hope the "vote-button" doesn't enable until we have
played at least 20 boards with/against other players.

I guess we agree that the current method (self-rating) is useless.

Many people (those with regular BBO partners and friends for example) do not need any ranking scheme.

So know we can remove ranking entirely from BBO and assume that it would not bother that many people at all if we did. Alternately we can assume that there are a few players who actually care for some kind of ranking method that is more accurate than the current one. Todd has proposed one and I guess we should give it (or a similarly promising approach) a go.

BTW a part of Todd's algorithm takes care of disabling the vote button until enough boards have been played with a partner.

In the end, everybody is free to ignore any rating figures that appear on a players profile - I for my part would like to have something a bit more valuable than the current self-tagging.

--Sigi

[DrTodd13]

Yes, any ratings scheme should have a purpose in mind. I think the purpose of the self-rating scheme (and the rest of the profile in general) was exactly to be able to facilitate picking partners and opponents to maximize your enjoyment of the game. (If we wanted a "measure your own performance" system then we could use lehmans and keep everyone's lehman number secret.)

I think the only thing we might all be able to agree on is that we don't know what the optimal rating system is (including no rating system at all) to best facilitate the goal stated above. Another thing I know is that we'll never know whether something works unless we try it. I can understand Fred's reluctance to offer something that could hurt people's egos. It is too bad you can't try this system in a microcosm. You have to have a lot of people before you can tell whether the system is useful or not. I might suggest that people not even be able to see there own ratings but we all know that people would find out anyway.

Would we rate opps? I have oscillated on this one. At this point, I believe this could be useful. We are probably a bit less passionate about opps than partners and less willing to blast them or try to artificially boost them but perhaps the weight shouldn't be as high for opp rating.

I don't think the "vote button" should appear only after 20 hands. My proposed weighting system would largely solve the problem of play 1 hand, decide partner is an idiot and give a terrible rating. Your rating wouldn't have hardly any weight if you've only played one hand with the person. Imagine a situation where there is a real jerk who people can't tolerate for more than a few hands. This jerk has a few regular partners who can tolerate him and they give him decent ratings. If you only let his regular partners rate him, then you will miss the fact that the guy is pretty much a jerk and drives away the vast majority of his pick-up partners. People can behave terribly when they are anonymous but when they are concerned about their reputation then their behavior will improve.

About the prisoner's dilemma thing, the idea may have some merit but I think the granularity may be too coarse. I would be open to trying the idea though.

Another thing I just thought of is that you may be able to detect the people who perpetually give a lower or higher rating than average and to lower the weight of their ratings or possible do something else.