Houdini leads, Stockfish and Rybka 2nd and 3rd

Naum 4.2 scores in R5 of TCEC, Rybka and Stockfish victorious in R6
Rybka jumps into third position

Naum 4.2 was the only engine to achieve victory in R5 of TCEC. It defeated Ivanhoe B47cB, after axploring a long term slight advantage to squeeze out the full point. In another exciting game of the day, Houdini 1.5 got a good position against Critter 0.9. The latter defended perfectly and got out of the difficult situation of rook immobility, turning around the game and even gunning for a victory itself. However, Houdini also defended well and preserved the status quo, the game ending in a draw.

Rybka 4 was again in difficult situation in R5, this time against Hiarcs 13.2. The World Champion used strong tactics to covert the game into a draw despite the positional problems. In the last game of the day Stockfish 2.0.1 could not achieve more than an opposite color bishops endgame and thus shared the point with Shredder 12.0.

Replay all games here

Round 6 started with a bang, as Rybka 4 destroyed Shredder 12.0. Rybka got advantage right from the start and quickly turned it into material and positional dominance on the board.

In probably the most interesting game of the round Stockfish 2.0.1 showed fantastic evaluation of the position on the board. Despite all machines having the same hardware, it looked to be always a step ahead of Naum. 35… Bf5 and 46… e4 gave the secure advantage and the full point to Stockfish 2.0.1, the engine that will be leading the commentary here for the upcoming Tata Steel (Corus) 2011

Critter 0.9 and Hiarcs 13.2 reached a theoretical draw as early as move 44, but they continued looking for options up until move 103 when a draw was signed.

Ivanhoe B47cB played a strong game against the star of the tournament Houdini 1.5. Problems for Houdini might have started as early as 12. Bd2. It proved to be a loss of tempo to moves like Rd1 or even b3. Ivanhoe B47cB put in full use the bishop pair, while Houdini was trying to find coordination for his pieces through the whole middlegame. There was light in the tunnel with a queenside break 26. b4, but Ivanhoe was again stable taking the center with 27. Bd4 and maintaining the advantage. Doubling the rooks on the open f file and fully using the advantage of the centralized bishop, little hope was left for Houdini. However, a dubious 36… Be8 instead of …Bc6 released some of the pressure, and Houdini immediatelly went for creating an opposite color bishops game. A nice attempt with 45. e6 hoping for … Bf6 was strongly met with …Rd2, creating the line opportunity 46. Bg2 Rff2 47. Rcd1 Rfe2 48. h4 Rxd1 49. Rxd1 Rxe6 50. Bf3 Rb6 51. Kg2 Rb2+ 52. Kh3 g5 53. hxg5+ Kxg5 54. Bd5 Rf2 55. Re1 Rf5 56. Bc4 Rf8 57. Rf1 Re8 58. Kg2 Ra8 59. Bd3 Ra3. Houdini risked even more with 45. e6 and 46. Rf1, trying to find a way to a draw, and the key to it was tablebases. More than 40 million hits were registered there before even reaching tablebases number of pieces. That reference secured Houdini 1/2 points and a saved day for the leader.

Houdini 1.5 is still full 5 points ahead in the general standings. The new version of Stockfish proved expectations so far and is having a regular +2 = 3 -1 performance for a clear second place. After the victory Rybka is in the top part, but also a loss away from the bottom of the table.

The TCEC tournament is a double round robin, thus more than half of the games are yet to be played. The ultimate goal for the engines is reaching the top two positions, as the number 1 and number 2 in this division will meet in the Elite match to determine the winner of the season.

Standings after Round 6

3 points for win, 1 for draw, 0 for loss

1 Houdini 1.5 14
2 Stockfish 2.0.1 9
3 Rybka 4 8
4 Ivanhoe B47cB 7
5 Naum 4.2 7
6 Critter 0.9 5
7 Hiarcs 13.2 5
8 Shredder 12.0 4

Official site of TCEC / Houdini official site / TCEC round 3 report / TCEC round 4 report