21 November 2016

TCEC Season 9 Superfinal Week 2

A week has passed since I posted TCEC Season 9 Superfinal Underway, at which time I noted,

In the nearly three days since the event started, the engines have played 12 complete games non-stop with Stockfish leading Houdini by +3-0=9.

Since that post, another 28 games have been played with a score of +4-2=22 for Stockfish, all of the last 13 consecutive games ending in a draw. Adding the two weeks together gives a current score of:-

+3-0= 9
+4-2=22
-------
+7-2=31

A Stockfish win in game 17 provoked a genuine controversy. The final position of Queen vs. two Bishops is shown in the following diagram, Black to move.


tcec.chessdom.com/archive.php?se=9&sf&ga=17

A long thread on the Talkchess.com forum, Cursed win at TCEC, started,

Engines showing 0.00 due to 50-move rule, but position was auto-adjudicated as an M72 TB win.

If you don't speak engine jargon, 'M72 TB' translates to a tablebase mate in 72. In other words, both engines abandoned the game as a draw because the mate will take longer than 50 moves to achieve, but the organizers adjudicated it as a win for Stockfish, playing White. Whether you think it should be scored as a win or as a draw, the final position is bad news for fans of the Sicilian Dragon, in particular this variation:-

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 g6 6.Be3 Bg7 7.f3 O-O 8.Qd2 Nc6 9.Bc4 Bd7 10.O-O-O Rc8 11.Bb3 Ne5 12.h4 Nc4 13.Bxc4 Rxc4 14.h5

The other game where the same line was played, Houdini as White, also ended in a win for the first player. At the end of the 'Underway' post, I extrapolated the score at that time to a crushing win for Stockfish:-

We're looking at something like a +25-0=75 final score, where isolated wins for Houdini will be the exception.

While the end result won't be that one-sided, adding the current score (+7-2=31) to a new extrapolation for the unplayed games (+10-3=47) gives a final score of +17-5=78 in favor of Stockfish. With 60 games still to be played at the rate of four games per day, we're looking at another two weeks of TCEC season 9.

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