Season 6, stage 4, round 27, Stockfish - Houdini, Ra2
Game on TCEC archive
This game was played after half of stage 4 was over. After 8-RR Stockfish was at +6, Komodo was +4 and Houdini was +3. It was generally accepted that Stockfish was better, but Houdini was still a very strong opponent able to hold its ground, even against top engines.
After the 8 moves of the pre-selected opening each engine made its first move, and according to their evaluations there was nothing exciting going on. Then came Stockfish's 10th move:
Ra2. The crowd went slightly wild. The rook doesn't usually move forward so early in the game, and here Stockfish was hinting that it may use the empty second row to move a second rook to the king side quickly.The game continued with Stockfish preparing an attack on the king side and Houdini countering on the queen side. Houdini's evaluation remained drawish, it only started to sense the danger on move 18:
The rook is still on a2, waiting for its chance. In a few moves Stockfish opened the king side with a pawn attack, the evaluation skyrocketed, and then on move 25 the rook moved.
With so much firepower directed against its king, Houdini admitted defeat. The game was terminated on move 29 !!! Another WOW. In a match between two top engines this was almost unheard of. And of course there was Ra2. Ra2 was suggested in the chat as a move to change games around quickly, with laughs all around.