[brian_m]

matmat, on 2011-December-04, 13:52, said:

Here's a novel idea. Stop trying to use your BBO IMP scores to gauge how good you are at bridge.

Maybe I'm the only one in this thread who plays in a regular game (though I very much doubt it). The IMP score is a simple way to come up with some kind of measure as to who's got the better of a 20-30 board session amongst players of comparable strengths. Why does wanting to minimise the distortions caused by the idiotic results imply anything about trying to assess "how good we are at bridge"?

Here's a novel idea for you. Stop trying to be a smartarse.

[matmat]

brian_m, on 2011-December-04, 15:42, said:

Maybe I'm the only one in this thread who plays in a regular game (though I very much doubt it). The IMP score is a simple way to come up with some kind of measure as to who's got the better of a 20-30 board session amongst players of comparable strengths. Why does wanting to minimise the distortions caused by the idiotic results imply anything about trying to assess "how good we are at bridge"?

Here's a novel idea for you. Stop trying to be a smartarse.

so who gets to decide what is an idiotic result and what isn't? is one pair in 16 making a slam they bid on a favorable lead idiotic if the rest of the field is taking the same number of tricks in game? is a couple of players making 3n on an exotic squeeze when the rest of the field is off idiotic? who are you to judge? If you have a set game, perhaps it wouldn't be that much more of an effort to set up a set team match, then you really don't have to worry about the rest of the bbo field.

[brian_m]

matmat, on 2011-December-04, 17:30, said:

so who gets to decide what is an idiotic result and what isn't? is one pair in 16 making a slam they bid on a favorable lead idiotic if the rest of the field is taking the same number of tricks in game? is a couple of players making 3n on an exotic squeeze when the rest of the field is off idiotic? who are you to judge? If you have a set game, perhaps it wouldn't be that much more of an effort to set up a set team match, then you really don't have to worry about the rest of the bbo field.

I didn't say anyone should decide what was an idiotic result, and certainly not that I should do it. I just noted their existence.

If you look back through the thread, and perhaps read a little more carefully, you'll see that my suggestion is that the number of plays of each board be increased, and then the top and bottom result be disregarded. There would need to be a little more thought put into this - the pairs concerned still keeping their scores, but their scores being disregarded for cross-imping the rest of the board (although I can't honestly see a problem with a Butler-type calculation).

And no, I'm not saying that one pair getting into a massively anti-percentage slam and then making on a lucky lead is an idiotic result. Lucky, yes, idiotic, no. What I'm calling an idiotic result is those in the 7NT**-7 sort of category. Perhaps boards where a pair goes down more than three tricks redoubled should be automatically flagged for review, to see whether the pairs concerned are just playing silly buggers.

And so another straw man is (hopefully!) laid to rest...

As regards your suggestion of playing team games - they're rather difficult to arrange with only four regulars, but if there are another four players reading this who play a set game starting around 7pm New Zealand time, I'm more than happy to try to set something up, please send me a private message.

[fred]

hotShot, on 2011-November-25, 18:03, said:

The 16 Board limit was introduces when BBO still was very small (less than 100 player online) and it took ages to complete a board.
The limit was hard coded into the Windows-Client and and that limit propagated into the server software.
One day the support of the Windows-Client might end and after that the 16 score limit will hopefully be history.

That is correct. The Windows client cannot handle more than 16 plays per board and that is not going to change. Our server software also has some hardcoded assumptions about 16 boards, both it would be relatively easy to change that.

It is possible that we will eventually open a new area on BBO for web-client users only with various features (like more than 16 plays per board) that are not supported in the Windows client.

Although we are not planning on changing or improving the Windows client, we have no plans to force people to stop using it. Our plan is to continue to improve the web-client with the expectation that more and more BBO members will continue to migrate.

I very much doubt that we will change the way we score boards. If we ever do, such change(s) will take effect for web-client users only.

Fred Gitelman
Bridge Base Inc.
www.bridgebase.com

[xarlos]

Mbodell, on 2011-November-25, 02:02, said:

Throwing out data will result in worse results overall. All data should be valid. The right fix is to compare with more than 16 other tables, which is possible in tournaments, if not in normal play.

I disagree. Throwing out extreme data (2sd+ from the mean) will result in regression to the mean.

[hrothgar]

xarlos, on 2012-January-19, 15:00, said:

I disagree. Throwing out extreme data (2sd+ from the mean) will result in regression to the mean.

Regression towards the mean has a specific meaning.
It involves adding samples rather than discarding observations.

Please feel free to try again...

[mgoetze]

gwnn, on 2011-November-29, 03:41, said:

The imp table is designed around common bridge swings such as 480 vs 980, 170 vs 620 etc.

A possible solution would be to compare against the median rather than the mean.

[barmar]

mgoetze, on 2012-January-23, 17:06, said:

A possible solution would be to compare against the median rather than the mean.

This might even be a good use for the least-used type of average, the mode, i.e. the most common result.

[Quartic]

mgoetze, on 2012-January-23, 17:06, said:

A possible solution would be to compare against the median rather than the mean.

barmar, on 2012-January-24, 13:23, said:

This might even be a good use for the least-used type of average, the mode, i.e. the most common result.

The problem here is when there are two normal, but significantly different results on the board, say +620 and +170.

[Wayne_LV]

What if?

Rather than generating hands using a random number generator, use hands that have been played in ACBL tournaments and/or club games. Compare results, not with the BBO field, but with the field that played in the ACBL game. I know that would involve substantial data entry but could this not be done with volunteers. To cross verify accuracy, assign a set of boards to 2 diff volunteers and then cross check the boards to make sure they match. If they don't match hand for hand, board for board, discard that set of board.

Another possiblility would be to use BBO records for hand hands played in BBO ACBL tournamnents for comparison and scoring in the "club" games. The likelyhood of someone playing a board in a tournament and getting the same board in a club game is next to nil, and if it did happen who would remember it?

I agree that the current method is not good, especially on weakends (pun intended) when weak fields are the norm.

[RunemPard]

I see a lot of people saying "start a team match...", yet, I never see any team matches to join. If I attempt to make a team match, no one ever joins to begin with.

I would like to see a better team match system.

[barmar]

Wayne_LV, on 2012-February-24, 11:29, said:

[font="Arial"]What if?

Rather than generating hands using a random number generator, use hands that have been played in ACBL tournaments and/or club games. Compare results, not with the BBO field, but with the field that played in the ACBL game.

I think this would violate the bridge law that says that hands must be dealt randomly. You're allowed to ignore this law for special events, like Instant Matchpoint tournaments, but normal games should be random dealing.

[phil_20686]

RunemPard, on 2012-February-24, 16:35, said:

I see a lot of people saying "start a team match...", yet, I never see any team matches to join. If I attempt to make a team match, no one ever joins to begin with.

I would like to see a better team match system.

You need to use the windows client to see lobby chat. There are always people trying to start (BBO) expert team games.

[helene_t]

Play matchpoints instead, that is slightly more roboust.