Israeli chess program check-mates the masters

Deep Junior just won its seventh World Computer Chess Championship. Even the famous Garry Kasparov was no match for this smart program

(By David Halevi)

Deep Junior won its seventh World Computer Chess Championship in 2011

It was called “the most spectacular chess event in history.” But according to the man who played the machine – chess champ Garry Kasparov, who played and lost to IBM's Deep Blue chess computer in 1997 -- that experience paled when compared to another match he played in 2003 against the Israeli-developed Deep Junior chess program.

Deep Junior continues to rack up victories, mowing down the chess competition -- human and binary. In November 2011, the program racked up its seventh World Computer Chess Championship award, presented by the International Computer Games Association.

The five games Kasparov played against Deep Junior were traumatic enough to prompt him to ask for a draw in the scheduled sixth game, preserving his reputation as a grandmaster – and the dignity of the human race, as well. After all, if the highest-rated chess player in history couldn't beat the program developed by Israelis Shay Bushinsky and Amir Ban, what hope is there for the rest of us?

Bushinsky says Deep Junior is ready to take on any comers, including any that
IBM or any other technology company cares to present.

Despite its status as the “king's game,” chess competition is rough-and-tumble, with insults thrown between competitors, bookmaking and wagering, and even cheating scandals. The same holds true for computer chess, and since it was first introduced in 1993, Junior (now dubbed Deep Junior, as it is deployed on multiple-processor PCs) has consistently scored at or close to the top of all of the many competitions in which it has participated.

It won the title of best computer chess program in the world in 1997, 2001, 2002, 2004, 2006, and 2011 – and in 2009 was awarded joint world championship honors with two other programs, after the nominal winner (a Czech program called Rybka) was stripped of its championship titles when it was discovered that part of the program's code was plagiarized.

Why Junior is tops

Bushinsky -- who teaches computerized artificial intelligence at Tel Aviv and Haifa universities -- has been with Junior from the beginning, rewriting and tweaking it to keep up with the competition.

“I've been involved in competitive chess since I was a kid, and was actually one of the top-rated teen players in Israel at one time,” says Bushinsky. “When I started getting into programming I kept up with my chess, eventually writing programs that we would develop into Junior with my colleague Amir Ban.” Ban is a founder of Israeli flash-drive pioneer M-Systems (since acquired by SanDisk).

Bushinsky offers some insights on why Junior is better, describing a program
that has the capacity to “learn” from its mistakes. “The system can review
previous games -- both its own and its competitors' moves -- and make decisions
based on what direction it believes the game is going in,” Bushinsky says.

Chess lends itself to being played by computers because it is a zero-sum game, with a limited (although very large) number of moves and countermoves. In fact, in chess championships, computers are in charge of all moves, even if the human players actually move the pieces on the board (“to put on a good show for the audience,” says Bushinsky).

Since programmers have access to the same databases of available moves, all
computer chess programs should be more or less the same. However, each program, including Junior, has its own little tweaks that can put it ahead of the pack.

Junior uses “opponent modeling,” meaning that the program plays moves that
are not objectively the strongest possible, but are geared more toward the
weaknesses of the opponent. One consequence of this “attitude” is Junior's
willingness to sacrifice pieces. Kasparov was reportedly so rattled by Junior's
unexpected 10th-move sacrifice of its bishop in game five of the 2003 tournament, opening up his king to a frontal attack, that he apparently realized
he probably couldn’t win game six.

Kasparov faced a similar sacrifice situation in his 1997 match against Deep
Blue, but somehow his experience with Junior proved more difficult, he told
sports cable network ESPN2 after he offered a rare draw in game six.

“I have to congratulate the Israelis programmers Shay Bushinsky and Amir Ban,
who did a superior job,” the chess master said afterward. “Deep Junior is a
significant step forward in developing chess software. I think Deep Junior is so
far the best computer chess program ever.