[mikeh]

whereagles, on Dec 13 2007, 06:52 AM, said:

I would rate expertise by measuring the average nr. of errors per board. In 20 boards, for instance,

<1 error: master (worthy of national team)
1: expert
2-3: adv
4-6: int
7+: newbie

I assume you are joking

One of the problems with this type of analysis is that most players don't know that they have made a mistake.

In fact, one of the hallmarks of the improving player is that he will feel he has regressed when all that has happened is that he is now seeing mistakes previously undetected, but seeing them after making them, not before. Sometimes, ignorance is bliss.

There are a host of mistakes that will pass unobserved by a less-than-expert player. And I am morally certain that the few error-free sessions I have ever thought I played were in truth flawed in ways too subtle for me to detect.

MY own observations suggest that the average player with (in NA terms) say 300-500 mps makes an average of 2-3 mistakes per board!

Bear in mind that a mistake does not carry with it any automatic penalty. Indeed, all good players have frequently experienced losing imps or getting a bad board from a technically correct bid or play, missed by the opps or the field. Bad bridge can actually lead to success, which explains a lot about the game: why it is difficult to improve, why so many players don't see mistakes they've made, and why the game is so challenging... if every mistake cost, most of us would have quit a long time ago.

[whereagles]

mikeh, on Dec 13 2007, 06:14 PM, said:

One of the problems with this type of analysis is that most players don't know that they have made a mistake.

I'm taking clear errors that had, or could have had, concrete consequences. I'm also referring to those errors in an abstract way. Whether or not people notice them is irrelevant.

Obviously, the table can vary (say add 2 errors per category), but I wasn't joking. Why should I be joking on this subject and context?

[Tomi2]

sceptic, on Dec 13 2007, 09:43 AM, said:

100,000,000 ?

how can you fit all these into 5 or 6 catorgorys

[/B]This overrating starts with star players in BBO. Somehow players from my country Germany recieved a star for winning one major national championship but this only qualifies them as "Expert"

if you take this 100 000 000 and try fo find a fair method to split them into 5 groups, then 2 ideas come into my mind at once:

every group is as bis as the other:
that means there should be 20 000 000 WC, 20 000 000 Exp etc.

this seems not logical but 1/5 of the players beeing expert is close to BBO standard. (now 8000 are online and 1600 are expert!)


the other way is to take 100 000 000 ^( 1/5) (thats nearly 40) and say:
There should be 40 players all over the world who should call themselves "worldclass"
There should be 40*40=1600 Players worldwide who should call themselves as "Expert"
64000 advanced
~2 500 000 intermediate
rest something like beginner

this would mean, that ALL WC and Expertplayers in the world are currently online

even a rating between "wolrdclass" players woulbe usefull:
There are 65 World Grand Masters alive (according the www.wbfmasterpinots.org), about 50 of them seem to be still active players, 15 did not imporve their rating in major international championchips in the past 10 yeras
some examples of this first group in BBO are alle the well known Italians, Americans etc. you see in the top list.
One of the 15 players who does not score that much anymore ist B.Garozzo

then there is a group of players, who often have good results in international competitions but do not qualify as WGM, they are called "Life Master" or "International Master", some BBO users as example:
Fred Gitelman or Larry Cohen (both WGM) or
his partner Bred Moss (WIM), T.Sadek- W- El-Ahmady (both WIM)

a 3rd group of BBO stars are players who once had inernational success or, as the definition says, have represented their country in a world championship.
That fits to many "junior" stars, every year there is a World Championship for juniors/schools, I participated in two of them already (so even I should have a BBO Star), next year will be my third, then there are events for women and seniors - same here- and there are many players who represented their country (say Australia or any other country where its not as difficult to qualify for the team as in USA, Italy etc.) in 1982.

so my idea for the ratingsystem would be to give 2 additional stars to players from the first group and one for group 2 members (Fulvio2002 would have *** rating then) and for all others:

maybe the BBO software could make it possible to rate your partner and oponents after each match / tournament. So everybody who would be interested in a reting system could first "selfrate" him self and all his partners and oponents could chose 3 options:
"I think his rating is too low - he seens better than he rates him self"
"I think his rating is ok"
"I think he is overrated"
or somehing like "score this player on a scale between 0 and 10"
and then the scores are multiplicated with the #of boards you played against/with him and an average score is taken.

in your porifle you would see your rating and what others think about this

[han]

FrancesHinden, on Dec 13 2007, 06:40 AM, said:

Expert
Under my definition, it's quite easy: you are an expert if you have won a national competition. Now, depending on your country you will be more or less good (it's a bit easy to win national competitions in, say, Rwanda than it is in the US). It's also easier to win women's competitions than open ones (at least, it is if you are female), but the definition is clear.

World Class
Again, under my definition you are world class only if you have played for your country in the Bermuda Bowl, Venice Cup or World Juniors. Not much margin for error there. I'd probably admit people who have played in the Olympiad as well (even though this will include some pretty weak players globally speaking).

While your suggested rules are very clear, I think they are also very poor. A true rating should reflect how good players are.

[awm]

Well it's hard to get unambiguous ratings that make sense across countries. I'd go with something like:

Beginner -- Learned to play in the last year, unlikely to score above average in the local (open) club game.

Intermediate -- Can hold their own in local club games, often finishing around average but rarely winning.

Advanced -- Regular winner in local club games, almost never finish below average. Can hold their own in local tournaments, usually around the middle of the field. May have some tournament wins in local open events.

Expert -- Regular winner in local tournaments, rarely below average. Can hold their own in national tournaments, usually around middle of the field. May have a few national wins if playing for a long time or in a country with a small bridge-playing population. Would not be someone you'd pick to win in a major event like a European Championships or NABC, but would probably land around average in such a field.

World Class -- Regular contender in major events such as European Championships or NABCs. If playing for a long time and/or in a country with a small bridge playing population, or if eligible for restricted events (women, seniors, juniors) then will have multiple national wins and have represented country internationally. Will be a virtual lock to finish near the top of the field in any event entered.

[jdonn]

whereagles, on Dec 13 2007, 06:52 AM, said:

I would rate expertise by measuring the average nr. of errors per board. In 20 boards, for instance,

<1 error: master (worthy of national team)
1: expert
2-3: adv
4-6: int
7+: newbie

I think most newbies probably make about 5-6 noticeable mistakes per HAND. Most experts, probably 4 or 5 in 20 boards, on a close detailed analysis by a group of other experts.

[Stephen Tu]

Adam,

I like your proposed definitions a lot better than the current BBO ones. I've always felt like the current ones were rather vague, and especially left too little distinction between "expert" & "world class", since to me the people who "have success in national tournaments", at least in the U.S., are the same usual suspects who I would consider "world class".

[neilkaz]

Stephen Tu, on Dec 13 2007, 01:32 PM, said:

Adam,

I like your proposed definitions a lot better than the current BBO ones. I've always felt like the current ones were rather vague, and especially left too little distinction between "expert" & "world class", since to me the people who "have success in national tournaments", at least in the U.S., are the same usual suspects who I would consider "world class".

Completely agree here and hope BBO changes definations to something worded like this.

[awm]

A lot of the systems proposed depend too much on what people "have done." My concern is situations like this:

(1) Player A lives in a small country with few bridge players. He made his country's national junior team when he was in his twenties, basically because he was under 26 and could follow suit. They proceeded to get thrashed in the junior championships. Player A has never done much in open events. Player B lives in a large country with many bridge players. He didn't really get involved with bridge until he was in college, leaving him too far behind to make his national junior team. He has a full-time job (not bridge), but has played in a dozen national-level events in his country, finishing in the top ten several times but never winning. Who's likely to be a better player, A or B? Guess who gets a star on BBO and is rated as "world class" by most people's rating systems? Who might not make "expert" by Frances' system? Hmm....

(2) Player A has been playing bridge since he was in college, and has been retired for the last ten years. He's played in over a hundred national events in his country, with one win and a half dozen other top ten finishes. Player B has been playing bridge for five years while working full time. He's played in ten national events in his country, with no wins but four top ten finishes and always in the top half of the field. Who's likely to be a better player, A or B? Guess who rates as "expert" according to most people's systems? Guess who gets a star?

(3) Player A is a billionaire. He has played in a half-dozen top-flight national events, always on a team of six with the five best players his money can buy. They managed to make the finals of a major event once, but never won. Player B is a graduate student. He has played in a half-dozen top-flight national events, always on a team of six with five of his buddies from college. They managed to make the finals of a major event once, but never won. Who's probably a better player?

Tricky, isn't it?

[mike777]

Hmmm
1) What's the goal of this BBO rating system, any?
2) How do you measure the success in reaching that goal?

Or are goals and measuring success towards that goal not important?
Note I frame all of this in terms of our goal and success towards that goal...NOt repeat not how accurate the ratings are.

If you cannot even agree on the goal then nevermind

[hotShot]

jdonn, on Dec 13 2007, 09:19 PM, said:

whereagles, on Dec 13 2007, 06:52 AM, said:

I would rate expertise by measuring the average nr. of errors per board. In 20 boards, for instance,

<1 error: master (worthy of national team)
1: expert
2-3: adv
4-6: int
7+: newbie

I think most newbies probably make about 5-6 noticeable mistakes per HAND. Most experts, probably 4 or 5 in 20 boards, on a close detailed analysis by a group of other experts.

Using a program that analyzes lin-files I found that (looking at cardplay only) GIB (using the money bridge settings) makes one error in 3 boards => 7 in 20 boards.

Using lin-files of vugraph events I watched, I can tell that WC and expert player can reach a level of 1 error in 5 Boards => 4 in 20 Boards.

Intermediate BIL members I played with, are in the area of 14-18 errors in 20 boards.

[mike777]

hotShot, on Dec 13 2007, 03:58 PM, said:

jdonn, on Dec 13 2007, 09:19 PM, said:

whereagles, on Dec 13 2007, 06:52 AM, said:

I would rate expertise by measuring the average nr. of errors per board. In 20 boards, for instance,

<1 error: master (worthy of national team)
1: expert
2-3: adv
4-6: int
7+: newbie

I think most newbies probably make about 5-6 noticeable mistakes per HAND. Most experts, probably 4 or 5 in 20 boards, on a close detailed analysis by a group of other experts.

Using a program that analyzes lin-files I found that (looking only at cardplay only) GIB (using the money bridge settings) makes one error in 3 boards => 7 in 20 boards.

Using lin-files of vugraph events I watched, I can tell that WC and expert player can reach a level of 1 error in 5 Boards => 4 in 20 Boards.

Intermediate BIL members I played with, are in the area of 14-18 errors in 20 boards.

How does your program define an error and why is that the correct definition compared to other commonly accepted ones?


Again if we cannot even agree what an error is why bother?
Are all errors weighted equally, why?
Can bidding or lack of bidding induce cardplay error? If so how do you define it and weight it?

[whereagles]

guys, my idea is simply to rank people according to average mistakes made. The exact amount is just a gauge thing. It don't matter much whether

1-2 = expert
2-4 = adv

or

10-20 = expert
20-40 = adv

[awm]

Errors are hard to define though. The tricky part is:

(1) Some "errors" on a double-dummy basis are actually percentage plays. Others are pretty much just guesses. This causes things which are actually not errors to show up as errors. Similarly sometimes low percentage actions work out, and therefore appear to be non-errors. Admittedly this type of thing may even out over the very long term.

(2) Some errors are things like not signaling clearly or correctly, or not making a defense easy for partner. In these types of situations no "double dummy wrong play" was made, or perhaps one was made by partner. In fact I find that the majority of errors made by top class players are frequently of this category -- they defend in a way which is not (double dummy) wrong but their choice of play or signal later puts partner on a guess which he gets wrong.

(3) Some errors such as not finding "mandatory" falsecards simply do not effect double-dummy results, but still make opponents' life much easier.

(4) Many errors occur in the bidding, where it is much harder to analyze who is at fault or what the right decision might be. There are situations where the right call depends on partnership agreement or the skill level of partner or the opponents.

I find that, watching top players, they rarely make absolute bonehead plays that are obviously wrong (okay maybe in the late stages of a long tournament we see a few). On the other hand, there are many subtle "mistakes" of the kinds described above. In contrast, watching beginners and intermediates the absolute bonehead plays come at a rate of a few per session, whereas the subtle mistakes (which often they wouldn't even understand if I tried to explain them) come at a rate more like several per board.

I know at one point I started counting the "absolute bonehead plays" I made per session and got very happy when the rate started to look like less than one per session. For a while I felt like "wow I'm good now" until I started realizing the number of subtle mistakes I was racking up was more like one per board...

[ArtK78]

mike777, on Dec 13 2007, 03:35 PM, said:

Hmmm
1) What's the goal of this BBO rating system, any?

When I play in the ACBL pair games on BBO, I use the opponent's self rating as a guide for the level of play that I should be expecting.

In addition to the self rating, there is also a symbol on each player's profile showing their cumulative master point holding on BBO. That also factors into the equation.

Of course, this only applies to those players that I have not encountered before. As I am playing more frequently lately, there are fewer and fewer opponents that I have not played against.

There are only a handful of true experts in the ACBL pair games on BBO, and I know them when I see them.

[mikeh]

whereagles, on Dec 13 2007, 04:23 PM, said:

guys, my idea is simply to rank people according to average mistakes made. The exact amount is just a gauge thing. It don't matter much whether

1-2 = expert
2-4 = adv

or

10-20 = expert
20-40 = adv

As Adam said, how we define error is important. Moreover, the better one is, the more errors one recognizes. Thus my take on the idea that an expert makes an average of 1 error per 20 boards says a lot more about the level of expertise of the poster than about the actual error rate of an expert

wc: 1 error per 20 boards if fresh, and rested.

recognized: almost all of them

expert: 4 - 10 errors per 20 boards, none of them bone-head unless fatigued
recognized: 2-8

advanced: 10-20 errors per 20 boards, probably 1 bonehead
recognized: 5-10

intermediate: 20-40 errors per 20 boards, 3-6 bonehead
recognized: 5-10

beginner: 40-100 errors per 20 boards, 20 of them bonehead.
recognized: 5-20

By recognized, I mean errors that the player realizes, then or later, without prompting by others.

By errors, I mean plays that are technically lower percentage than an alternative equally valid on the hand to the time of the play, or bids that are, in the context of the methods chosen, demonstrably inferior to an alternative.. and includes such things as failing to give partner help on defence, or failing to draw the correct inference from opposition action or inaction, provided that the inference that ought to have been drawn is valid. I do not include percentage action that fails on the hand, or falling for clever play by the opps, etc.

But it really doesn't matter The measure of a good player is the partners and teammates who ask him or her to play. Respect of peers is the only true measure.

[whereagles]

mikeh, on Dec 13 2007, 09:54 PM, said:

my take on the idea that an expert makes an average of 1 error per 20 boards says a lot more about the level of expertise of the poster than about the actual error rate of an expert

You know why you'll never be a good player? You waste too much time bickering with others instead of improving your own game. I, on the other hand, won't bother with you. Have a nice day.

[mikeh]

whereagles, on Dec 13 2007, 05:08 PM, said:

mikeh, on Dec 13 2007, 09:54 PM, said:

my take on the idea that an expert makes an average of 1 error per 20 boards says a lot more about the level of expertise of the poster than about the actual error rate of an expert

You know why you'll never be a good player? You waste too much time bickering with others instead of improving your own game. I, on the other hand, won't bother with you. Have a nice day.

Thanks for the tip

[hotShot]

mike777, on Dec 13 2007, 11:02 PM, said:

How does your program define an error and why is that the correct definition compared to other commonly accepted ones?


Again if we cannot even agree what an error is why bother?
Are all errors weighted equally, why?
Can bidding or lack of bidding induce cardplay error? If so how do you define it and weight it?

These are indeed interesting questions, but I look at it from a practical point of view.

I have a list of about 250 player from which I watched or played more than 40 boards, I find that world champions and our national champions are at the upper end of this list, while BIL member find their place at the lower end of he list.

If I'm interested in a players true rating, I can get me a bunch of boards from myhands and calculate the average error rate. Thats good enough for me.

[awm]

The error rate idea does work a heck of a lot better if you restrict to declarer play. Now things like signaling partner are removed from the equation. You still get a bit of an effect from the opponents (good opponents will find mandatory falsecards and such that make double-dummy play more difficult for example). And of course there is the effect that the right percentage play isn't always the right double-dummy play. But the latter effect should tend to cancel out over a very large number of boards. Obviously it's not right to call this really "error rate" because someone who plays every hand single-dummy perfect will not have a perfect "zero error rate" here. But you'd expect that good players generally take higher percentage lines and therefore produce fewer non-double dummy plays over the long term.