Season 12 live blogging, Friday Apr 20th

Season 12 has started with division 4, a 4RR with eight engines, the top two will qualify for division 3. The games are about an hour long each and we are about half way through the second RR. Ethereal is leading, with Rodent and Xiphos close behind, it is likely that 2 of these three engines will promote.

A lot of interest in this division is the new NN engine Leela chess zero (LCZero). It entrered the competition at the last moment and has a lot of fans, many people are donating their computing resources to help train Leela. So far it is not doing well, usually it blunders in teh middle or end game. However it is always interesting to watch. There is a good chance that next TCEC season it will do much better.

The Leela - Tucano game is just starting.

move 6 - evals are close to 0, Tocano's just turned slightly negative. This is not a very popular line for QGD, but there are some GM games with this line, so it is playable.

move 10 - Leela is pushing pawns on the queen side, its king is still in the center. The bishop on b2 has control of the long diagonal. Tucano is ahead on developement.

move 14 - Leela opened the queen side, it should get its king to safety soon.Tucano's eval is increasing gradually.

move 21 - Tucano is a pawn up after a series of exchanges, eval over 1. Leela is finally ready to castle, but it will have to defend to hold the game. Will the black pawn majority on the queen side be enough for a win? Will Leela blunder?

move 24 - The engines exchanged a pair of rooks and only QRB vs QRN remain. Leela usually blunders the endgame, and this game is heading to a B vs N endgame with black a pawn up.

move 27 - Tucano has a rook on the 2nd rank, its eval is over 1.5. It's too bad it has no PV and we can't see what it is planning.

move 31 - Tucano's eval continues to increase, over 2 now. The remaining rooks are off the board and Leela may lose another pawn soon.

move 35 - I don't see how Leela can stop the queen side pawns in the long run. It's trying to counter on the king side but the queen alone cannot do a lot.

move 38 - there is a black pawn on d3, it will cost Leela the bishop. Can it do something with its queen and pawns on the king side? Leela's eval is still below 1.5.

move 44 - Leela is still optimistic but Tucano's eval is over 6 and it is winning the Q vs QN ending.

move 55 - soon Leela will run out of checks, it is a knight and pawn down and it's just a matter of time now.

I don't think Leela blundered badly in the game, perhaps it gave away a pawn too easily. Once it lost the second pawn and Tucano started to march on the d file Leela lost a piece and the game.