Monday, January 14, 2019

Season 14 premier division after RR5

Crosstable after RR5

After 2 clean RRs KomodoMCTS crashed for a third time and was disqualified. It keeps playing but the results of all its games in the division will be ignored. As a result the actual crosstable is not as it appears in the live and archive sites. After 5 RRs the standings are: 

Stockfish +12, Leela +3, Komodo +2, Houdini +2, Fire -4, Ethereal -7, Andscacs -8.

Stockfish is still unbeaten in the division and will qualify for the superfinal. Leela, Komodo and Houdini are fighting for the second spot with Leela 0.5 point ahead. Leela lost twice in this RR, its worst RR so far in the division. This allowed Komodo and Houdini to get close and now the race is very close and every game counts.

KomodoMCTS was disqualified and it will be relegated back to division 1. The other engine to be relegated is one of Ethereal and Andscacs. Fire is still in danger but has a comfortable gap of 2 points from last place. Ethereal has no wins in the division yet it is 0.5 points ahead. The engine that loses less games will survive.

Leela suffered 3 losses in 4 games, including one from the previous RR. This led to a check of the GPU hardware and it was found that there was a problem with the GPU fan setting. However this problem probably started from division 3, recall that Leela won 3 divisions convinvingly and it is close to reaching the superfinal in the premier division. As a result the organizers decided against replaying any games.

There were a few one-sided openings in this RR, the reverse games should be exciting to watch.

A few interesting games

Stockfish - KomodoMCTS: Stockfish had an eval advantage of about 1 from the start, and it gradually increased. The black pawn line was mostly on the 6th and 7th ranks, leaving very little room for the pieces to move. Stockfish attacked on the king side, KomodoMCTS surrounded its king with pieces so that it was vulnerable to knight threats. In a series of exchanges Stockfish won a bishop for pawns, later KomodoMCTS lost a knight to avoid mate and the game was adjudicated.

Komodo - Leela: See featured game below.

KomodoMCTS - Ethereal: KomodoMCTS had an eval over 1 despite being a pawn down. KomodoMCTS regained the pawn and the engines exchanged down to a double rook ending. Ethereal's pawn structure was weak, KomodoMCTS captured a pawn and created a majority on the king side. Then it exchanged a pair of rooks and captured a pawn on the queen side, leading to a won rook ending.

Leela - Houdini: Leela's eval was over 1 and increasing from the start. It had a pawn majority on the queen side that later became a passer on the 7th rank. Houdini gave a rook for a bishop to get rid of the passer and the game reached a RB vs BB position. Leela's eval peaked over 4 while Houdini's eval remained below 1. Leela tried hard but couldn't break Houdini's defenses, the game ended in a draw.

Stockfish - Komodo: After a series of early exchanges Stockfish was up a pawn and had an eval over 1.5. The engines played out a long PV agreement that ended in a RB vs R position, Komodo two pawns up. It took Stockfish a while to convert the win. After a few pawn exchanges the white rook got behind the black pawns and started to attack them. The game was adjudicated before Stockfish started to push passers on the king side.

Komodo - KomodoMCTS: KomodoMCTS went a pawn up after several early exchanges, Komodo's eval was over 1 and increasing. In another series of exchanges Komodo won a knight and the game reduced to a RN vs R ending. KomodoMCTS saw it was losing and it gave up, letting Komodo capture its pawns and rook.

Fire - Leela: Fire had an eval advantage from the start, Leela's eval jumped over 2 very early while Fire's eval was below 1. Material was equal and the engines exchanged pieces, Fire went a pawn up only on move 30, Leela's eval was already over 7 at this stage. The game reached a knight ending and the pawns raced forward. Leela promoted first but Fire promoted with a check and had a second pawn on the 7th rank. Leela could give a few checks but this only delayed the adjudication.

Stockfish - Andscacs: Stockfish had an eval advantage from the start, its eval remained under 1 for the first 35 moves. Andscacs captured a pawn and the position opened up, Stockfish's eval jumped over 2. The black king was vulnerable to attack, Andscacs was busy protecting it and Stockfish used this to capture black pawns. The game reached a RN vs RB position with Stockfish 2 pawns up and the game was adjudicated after several more moves.

Featured game: Komodo - Leela
Premier division, round 29
Link to game on TCEC

Evals were close to 0 at the start of the game, even after Leela went a pawn up. The engines castled in opposite directions, Komodo moved its pieces to the queen side facing the black king and evals started to increase.

Leela offered a rook for a bishop for a few moves and its eval jumped oveer 1.5. Komodo waited for the right moment to take the offer, then the engines reduced to a QR vs QN position and Komodo's eval jumped over 2.

Both queens captured pawns, Leela cleared the king side and Komodo cleared the queen side. Komodo's eval slowly increased but Leela thought it was much safer than before. Leela's pawns had a head start but Komodo's king side pawns had a clear path, Komodo also had a rook on the back rank for protection. Leela was late in realizing it was heading for a loss.

Komodo's h pawn ran fast and queened. Leela also queened a pawn but lost one queen for the white rook. In the end Komodo had two queens to Leela's one, it was close to mate when the game was adjudicated.

No comments:

Post a Comment