Season 19 premier division, final results

 Final standings

 

Stockfish and Leela will play in the season 19 superfinal. This was the expected result, Stockfish and Leela led the division from the start and were in no danger of being overtaken by 3rd place AllieStein.

Fire and Ethereal are relegated to division 1. The struggle at the bottom of the table was very close until the very last round of the division. Komodo struggled from the start and was still in 7th place after RR6, but a score of +2 in the last two RRs ensured it would survive. Ethereal beat Fire but that wasn't enough to get it out of last place. Fire caught up with ScorpioNN after beating it with one round to go. It had a tiebreak advantage and it held a draw against Stockfish in its last game. ScorpioNN however beat Stoofvlees in its last game and survived, pushing Fire back down.

Interesting games

Game 169, Stockfish - ScorpioNN: Evals started around 1 and steadily increased. There was only one pair of pawns exchanged in the first 30 moves, then a series of exchanges opened the position and led to a Q vs RR imbalance, Stockfish's eval was over 4. Stockfish had a pawn majority on the queen side, and after a while it created passers. ScorpioNN tried to fight back with its own passer, both engines queened a pawn but Stockfish was first and it mated using its two queens.

Game 176, Stockfish - Leela: See featured game below.

Game 179, Stoofvlees - Fire: Stoofvlees' eval went over 1.5 early, the center was blocked and there was only one pair of pawns exchanged that opened a file on the queen side. Fire concetrated forces on the queen side, then gave a pawn and tried to attack but nothing came out of it. The engines exchanged pieces until reaching a knight ending, all the black pawns were blocked and Fire was close to zugzwang having to protect two weak pawns. The extra white pawn gave Stoofvlees the win.

Game 187, Komodo - Stockfish: Stockfish's eval was over 1 out of book, the black king was stuck in the center with no safe castling option. Komodo opened the king side with a knight sacrifice, then opened the queen side and reached a N vs R imbalance. The white bishops were strong, restricting the movement of the black pieces. Komodo captured a bishop and the game reached a BBN vs RB position. After Komodo captured two pawns it started pushing passers, Stockfish couldn't stop them without losing material.

Game 188, Ethereal - Fire: Ethereal pushed a pawn to h6 and its eval was close to 2 and increasing. After a while Ethereal started to exchange pieces, leading to a RN vs RN position. It then captured two pawns. creating connected passers on the queen side and making the h6 pawn a passer on the king side. Fire was forced to lose material and the game ended in a tablebase win.

Game 190, Stockfish - Ethereal: One pair of pawns was exchanged after the start. Stockfish's eval went over 1 and slowly increased, reaching 2 after a second pair of pawns was exchanged on move 30. Ethereal's pieces were pushed back and it had a weak knight in the corner. After a series of exchanges only RBN vs RBN remained and Stockfish went a pawn up. Stockfish reduced to a B vs N ending with a passer on the queen side and a pawn majority on the king side, the game was adjudicated a few moves later.

Scores after RR7: Stockfish +12, Leela +7, AllieStein +2, Stoofvlees +0, Komodo ScorpioNN -4, Fire -6, Ethereal -7. Stockfish and Leela continue to lead, though both lost a game for the first time in the division. Stockfish lost to Komodo and beat Leela, both reverse games should be interesting. Komodo's win is a big step away from the bottom of the table, Fire lost twice and it joins Ethereal as a candidate for relegation.

Game 201, Komodo - ScorpioNN: ScorpioNN was slow in developing its pieces and Komodo attacked on the king side. A knight sacrifice allowed Komodo to involve a rook in the attack and the black king ran to the queen side. Komodo captured pawns during the chase, then through a rook for knight exchange exposed the black king again. This time the attack ended in mate.

Game 203, AllieStein - Fire: AllieStein's eval was over 4 after it moved a pawn to h6. It may have missed a win, after a long shuffle evals came down as the engines opened the position and reduced to a QB vs QB endgame. AllieStein wouldn't lower its eval for the draw rule, the game ended in a tablebase draw only on move 274.

Game 205, ScorpioNN - Leela: ScorpioNN held a draw with a fortress in a RBN vs QR position, white 2 pawns up.

Game 210, Komodo - Fire: Komodo had a small eval advantage from the start, its eval stayed below 1 for a long time while the engines mostly shuffled. After move 60 Komodo's eval started to increase, the white pieces had more room to move and the black king was vulnerable. After opening the center Komodo captured a pawn, Fire was busy defending its king and after exchanging queens Komodo captured a second pawn. The game was adjudicated a few moves later.

The bottom of the table with 3 rounds to go: Komodo -2, ScorpioNN -5, Fire Ethereal -7. Komodo is almost surely safe after winning 2 more games. Fire and Ethereal are most likely to relegate but ScorpioNN still has to be careful.

Game 214, Leela - Stoofvlees: Leela had a bishop pair and Stoofvlees was a pawn up. For a long time the engines mostly shuffled and evals stayed low, then Stoofvlees captured a pawn on move 96 and this turned out to be a huge blunder. Leela quickly reduced to a R vs N ending, keeping one pawn safe to ensure the win.

Game 215, Stockfish - Komodo: Stockfish's eval went over 2 after it gave a knight for 3 pawns and cleared the black queen side pawns. The queens were exchanged and after trading a pair of rooks Stockfish pushed passers on the queen side. Komodo gave material to stop the passers, the game reached a RB vs BN ending. It took Stockfish another 20 moves before it was about to capture a pawn, and the game was adjudicated. There were two white wins in this opening.

Game 216, Fire - Ethereal: Fire was a pawn up in a RRB vs RRN ending. Fire may have missed a win, but Ethereal was able to exchange a pair of rooks and reduce to a tablebase draw.

Two rounds to go Komodo is safe 2 points ahead of Fire and Ethereal. 

Game 217, Fire - ScorpioNN: Fire had a small eval advantage from the start, which slowly increased until it was over 1 in a QR vs QR position on move 32. Fire was a pawn up with a queen side passer, both kings seemed to be safe and the engines shuffled for a while. I'm not sure whether ScorpioNN blundered, Fire was able to force a pawn move that exposed the black king. Fire let go of its passer and used mate threats to reduce to a king and pawns ending which was a tablebase win.

Entering the last round Fire manages to catch up with ScorpioNN, and the win means Fire has a tiebreak advantage. Ethereal is only 0.5 points behind, but it is unlikely it can escape relegation.

Game 221, ScorpioNN - Stoofvlees: Stoofvlees blundered early, ScorpioNN sacrificed a bishop for pawns and opened the king side. It took Stoofvlees 4 moves to realize its king was in danger, ScorpioNN attacked quickly and Stoofvlees had to give material to save its king. The game was adjudicated on move 34 in a Q vs B position.

Game 223, Leela - Ethereal: Leela had a bishop pair advantage, the engines shuffled for a long time with low evals. After move 60 evals slowly increased, Leela gave a rook for a knight and pawn opening a file in the center and threatening the black king. Ethereal gave the material back and the game reached a RB vs RN position with Leela a pawn up. Leela pushed a passer to the 7th rank, Ethereal blocked the passer and eventually captured it but Leela was two pawns up by then. The game continued for another 30 moves until Ethereal's eval was high enough for the win rule. 

Featured game: Stockfish - Leela
Premier division, game 176
Link to game on TCEC

Stockfish's eval was around 1 from the start and for the first 25 moves. After the engines exchanged queens Stockfish's eval started to increase. Leela gave a pawn to open a file on the queen side. It expected Stockfish to exchange rooks and give the pawn back, but Stockfish protected the pawn and kept the rooks and its eval went over 2.

Leela managed to drive the bishop away and open the c file for its rooks, however all its pawns were isolated and weak. Stockfish exchanged pieces until reaching a rook ending, it was a pawn up with a doubled pawn and had a pawn majority on the queen side.

Stockfish was confident it was winning while Leela's eval slowly increased. Stockfish created connected passers on the queen side and Leela's pawn advantage on the king side was not a strong enough counter.

Stockfish pushed a pawn to the 7th rank, Leela gave a pawn and countered with a pawn on the 2nd rank. The position was still a win for Stockfish, the game was adjudicated before reaching a tablebase win.