Why do Chess Engines Play so Much Better than Bridge Playing Computers?

The best chess engines play equal or better than the best human.

The duplicate bridge playing computers play at a relatively very low level. Maybe class C in chess terms.

There are many millions of bridge players on the internet.

You would think someone, somewhere could program a much better bridge playing computer. [they are called Gib at the site I play]

Of course, they know all cards played but when defending against a contract [especially defending against 3 No Trump] they are gadawful 

Duplicate Bridge is very complicated but chess is more complicated than Duplicate Bridge. 

Why  the disparity?

Probably because it's a multi-person game?

Most of the axioms of mathematical economics don't hold in a 3-person trading world. Once the model has more than 2 traders the math gets really nasty.  Perhaps the same kind of problem is present in progaming a "Bridge Engine?"

I conjecture a dedicated "Bridge Programmer" would know the quick and dirty answer to your question.

One possible reason is that in bridge you have incomplete information. Also, I think less time has been spent on computer bridge than computer chess.

Wikipedia is your friend. http://en.wikipedia.org/wiki/Computer_bridge

A few quotes:

"Bridge poses challenges to its players that are different from board games such as chess and go. Most notably, bridge is a stochastic game of incomplete information. At the start of a deal, the information available to each player is limited to just his/her own cards."

"In comparison to computer chess, computer bridge is in its infancy. Yet, whereas computer chess has taught programmers little about building machines that offer human-like intelligence, more intuitive and probabilistic games such asbridge might provide a better testing ground.

The question whether bridge-playing programs will reach world-class level in the foreseeable future is not easy to answer. Computer bridge has not attracted an amount of interest anywhere near to that of computer chess. On the other hand, researchers working in the field have accomplished most of the current progress in the last decade."

Bridge is like poker in that it is a game of partial information. There are plenty of online bots playing online poker at low limits. None are good enough to play for any significant stakes though. A good poker player can easily take advantage of the computer and clean up

Card games involves luck. Chess involves a lot of calculation, and computers are excelent in calculation.

So chess is near deterministic, and bridge is open and probabilistic.  Sounds eminiently plausible.

But Wiki seems to be leaning in the direction of -- "It's just a matter of time."  

Computers versus humans[edit source | editbeta]

In Zia Mahmood's book, Bridge, My Way (1992), Zia offered a £1M bet that no four-person team of his choosing would be beaten by a computer. A few years later the bridge program GIB,^[3] brainchild of American computer scientist Matthew Ginsberg,^[4] proved capable of expert declarer plays like winkle squeezes in play tests. In 1996, Zia withdrew his bet.^[5] Two years later, GIB became the world champion in computer bridge, and also defeated the vast majority of the world's top bridge players from the 1998 Par Contest (including Zia Mahmood). However, such a par contest measures technical bridge analysis skills only, and in 1999 Zia beat various computer programs, including GIB, in an individual round robin match.^[6]

Thanks much for the source.  I did not know that. 

I do know when I get one of the best Gibs where I play--the do not play

well at all. 

I play bridge on Monday nights and it is always against Gibs and

we almost always win. 

Maybe  there is a super Gib I do not know about?

Well then, is bridge not an intellectual game? Come bridge computer programmers! With super computers now more available get your act together! Who knows what the future holds!

I am also a chess player. There IS also luck in chess! Some people think there is no luck in chess. Nothing could be further from the truth! So where, one might ask, IS the luck in chess when all is seen before one! Well it's quite simple really.  There are many factors where luck enters the game of chess. There is luck if you may be up against an easy opponent; there is luck if you are up against a stronger opponent; there is luck if your opponent is not at his/her best at the time of play; there is luck if you are not at your best. Luck also has a bearing if you or your opponent, like in bridge, make a blunder. One can also get into time difficulties in a chess competition game. There is luck in other things in chess too; I could go on but I'll leave it at that for now! I welcome comments on my statement.

All of the things you mention have nothing to do with chess qua chess—they're all external factors.

Actually, the term 'luck' is kind of useless when comparing games, since it's so ambiguous. 'Random chance' would be a better comparative term. And chess, to the best of my knowledge, involves no random chance whatsoever (ignoring, for the moment, the possibility of a first- or second-move advantage, which could presumably be corrected for by playing an equal number of games as White or Black against each opponent).

I'm only vaguely familiar with bridge, but as I understand it, duplicate bridge (the variety generally played in tournaments and clubs) involves very little random chance, since you're being scored against how players at other tables play the same hand, not against your opponents. It does involve incomplete knowledge, though, like most card games and unlike chess. But again, I'm definitely not an authority on bridge (or chess, for that matter).

Recently a poker playing computer beat 6 poker pros. So, there is some hope that the duplicate bridge "Gib" will greatly improve.

There is some luck [random chance] in chess and in duplicate bridge and in poker.

However a strong player will do very well in all 3 games given enough time.

Again, by its very nature, there is no random chance in chess. Same with checkers (draughts), shogi, Go, xiangqi, etc.

Zip. Nada. Zilch.

Please stop spreading false information.

There is a lot of random chance in poker and duplicate bridge. There is some random chance in chess.

"There is some random chance in chess."

Well, no, there isn't, unless you count random ways of assigning who plays White, or if your opponent is chess software (such as "Play Magnus") that has some randomization in how it chooses moves. 

That's what I tried explaining to him, but it seems it's hopeless. For someone who enjoys chess so much, he sure seems to be lacking in basic reasoning skills...

For anyone else reading, though, no, there is no random chance in chess. There is no roll of the dice or shuffle of the cards, or any other element of randomness, period.

But then again, to anyone else, this should be self-evident and not in need of explaining, like saying 1+1=2 or 2x2=4. It's a mathematical fact.

The explanation probably has to do with the incalculability of the three-body problem in physics and astronomy.