Season 9, stage 3, RR 2

I was away for a few days and had to race through playbacks of the games, unfortunately TCEC waits for no man. At least the draw rate is still high, most of the draws I just glance at to see if anything exciting happened. I hope to get back to live viewing by next week.

Table after 2 RR

The draw rate is 38/56 (68%).
With the first two rounds over the table is split into a top half and a bottom half. There has been only one decisive game so far within the top 4 engines (Komodo - Fire), so anything can still happen. Houdini is within half a point of a superfinal spot, will it cause an upset this season?
In only 1/28 openings both engines won, Cato's opening choices continue to be successful, being just biased enough to show differences in strength of engines.


Some of the game highlights

Komodo - Houdini: There was a lot of interest in this game after the controversy of the first game of the stage. Komodo took the game to a different direction right from the first move. The eval advantage of the opening came down temporarily, and then went back up when Komodo won a rook for a bishop. The game reached a RN vs BB ending, and the evals around 1. Houdini defended very well, the bishops had pawn support and Komodo had no easy target. It took a very long time for the evals to get down but the game was a draw.

Rybka - Andscacs: Andscacs somehow got itself into giving a rook for a strong pawn position with three connected passers. Both engines saw that Rybka had the better deal, and though black got the material back white could sacrifice pieces to assure queening and win the game. Andscacs' loss was a bit of a surprise for me, perhaps the opening was too biased.

Stockfish was up a rook for a knight against Rybka, but the RRB vs RBN endgame was static and evals were only at 0.4. Both engines were playing on increment and the 50-move draw was getting close, but Rybka blundered the endgame allowing Stockfish to win a piece and the game.

Komodo was two pawns down against Andscacs but had a strong knight on the 6th rank and prevented black from castling. Andscacs' position collapsed when it allowed Komodo to attack the back ranks with rooks. After a series of exchanges the pieces left were QNN vs RRN, and with an exposed king and too many unguarded pieces black was lost.

Jonny was quite happy with the Q vs RRB, 4 pawns up position against Komodo. Komodo thought the best Jonny could do was get a draw, but then Jonny lost two pawns and Komodo had the initiative. With less pawns the black piece advantage became too strong, and the only defense was giving checks. It was slow and tricky, but Komodo got the win, double win against Jonny with this opening.

Fire - Rybka reached a QR vs QR endgame that looked drawn. Rybka's king was exposed to checks, Fire used this to gain a pawn. The position was probably still drawn but Rybka blundered the endgame and let Fire win another pawn and reach a won 6-man queen ending.

Gull - Houdini started with an eval advantage for Gull but Houdini exchanged pieces and equalized. Then, in a QRR vs QRR position Houdini started to dominate. The white king was vulnerable and had to be defended, and Houdini had a dangerous passer. The evals rose higher and higher, and after queens were exchanged the passer was worth a rook, game over.

Stockfish - Andscacs was more or less balanced for about 20 moves. Andscacs did not take Stockfish's king side attack seriously enough, and was very sorry a few moves later. Stockfish took a bishop for a rook and left Andscacs' king with very little defense, the game was stopped before its position collapsed. Four decisive games in a row, a full round.

Komodo played most of the game with a Q vs RN imbalance against Stockfish, but could not get past the Stockfish defense.

Andscacs - Gull was headed for a 50-move draw, but with both engines playing on increments Andscacs' eval started to rise. It started with a small crack in the pawn line, and after slowly exchanging pieces Gull's whole pawn line crumbled, Andscacs won a piece for a passer and reached a winning 6-man RNP vs R position.

Andscacs came very close to beating Jonny. It had a few choices of endgames with a pawn advantage, but the choice it made led to an opposite color bishop ending with two (doubled) pawns up, and it wasn't enough for a win. 
  

Featured game: Jonny - Houdini
Stage 3, round 13
Link to game on TCEC

Jonny had space advantage against Houdini, with the queen side pawns locked. The game started with an eval advantage for Jonny but Houdini equalized without too much trouble. 

Houdini then started to use the semi open king side to create pressure on the white king. Jonny couldn't get enough defenders and got into a lot of trouble very quickly, the evals now in Houdini's favor and increasing.

The king side opened up and after a few exchanges the white king had to run as the pawns around it were gone. The material was still equal but Jonny was under a lot of pressure.

Jonny exchanged pieces and was only a pawn down in a RB vs RN ending, but there was no way it could defend its pawns. A nice win for Houdini in black, still with a good chance to make it to the superfinal.