2012 Challenge Match
Preliminaries
The 2012 Challenge Match happened from April 7th to April 27th, 2012.
Omar chose Jean Daligault (Chessandgo), Tarou Asou (Hanzack), and Eric Momsen (Nombril) as defenders for this year's challenge. As of March 13th, Daligault and Asou were the two remaining players in the World Championship, while Momsen was among the top four, giving us arguably the strongest set of human defenders in the history of the challenge.
In 2012, as in 2011, the second place bot from the World Computer Championship won the screening phase. Although Marwin had won the computer championship, Briareus convincingly outperformed it by a score of 25-22 (Marwin fared better in just one game, against Ocmiente), with a performance rating of 2232. Although Briareus beat several strong players (including Boo, Max, Tuks, Fritzlein and Hippo), Adanac and Harren swept games against it, while Browni3141 and Ocmiente both showed scores of 1-0. Thus, going into the challenge match, most players thought that humanity would win.
The Challenge
In the first round of games, Hanzack played a risky opening and around move 13, observers thought his position was worse. However, after very sharp tactical play, he avoided any material loss, and gained a superior position before winning in 69 moves. In Nombril's game, he had an advantage against Briareus and was close to finishing it off, when the bot managed to conjure a goal attack of its own and steal the victory when Nombril overlooked a goal-in-1 threat. Chessandgo quickly established an advantage and won in 38 moves, only losing a cat on Silver's last move.
In the second round, Hanzack gained a dominating position as silver in the first ten moves, but then entered a somewhat more "open" position by move 15. By move 25, gold had a horse hostage and silver's advantage was less obvious. However, Hanzack then gained the advantage again and won in 64 moves, meaning that the challenge was successfully defended. In the second game, Nombril eventually lost after a grueling 93 move game that lasted six hours. After 70 some moves, he had a strong position, but opted to pursue a goal attack rather than gain material. Analysis later suggested Nombril had a 5 move forced goal, but did not capitalize on it. This marked the first time a top ten human player has lost a three game challenge match. Chessandgo won convincingly by taking control of one of Briareus's traps with minor pieces, which gave his strong pieces more freedom in the rest of the board, but then granted a camel for two rabbits trade which allowed the bot to prolong the game more than would be expected (to 66 moves).
In the third round, Hanzack beat the bot after giving a handicap of a cat and using an unusual setup with 7 rabbits forward. By all appearances, the bot actually seemed confused by the given handicap (likely specifically due to the setup), playing uncharacteristically timid, and Hanzack rolled over it with relative ease, never really being in trouble.
