Tong(QD) Xiao vs Chongsheng Zeng: game review

26.Nd3 is a mistake: White's winning chances go from 42% to 24%.

• Black answers 26…hxg3, which takes the pawn on g3.
• Better was 26.Bxe4 (−0.86), which takes the knight on e4.

Better: 26.Bxe4 wins a rook for a piece and a pawn. After 26…fxe4 27.Rc3 hxg3 28.Bxg3 Rxf4 29.Bxf4 Bxf4 30.Qf1, White comes out a pawn up (−0.86).

26…hxg3! The only good move here: every alternative is clearly worse.

• Takes the pawn on g3.
• Pushes a pawn towards the White king, to pry open lines in front of it.
• The next best move, 26…Bxd3, would drop Black's winning chances from 76% to 63% (−1.39).
• 26…hxg3 trades pawns.
• Trades pawns: trading pieces when ahead brings the win closer.
• Leaves White with an isolated pawn on h2: a long-term weakness.

31.Bxe4 is a mistake: White's winning chances go from 24% to 8%.

• Black answers 31…fxe4, which takes the bishop on e4.
• After fxe4, Black wins 3 points of material within 2 moves.
• Better was 31.Bg1 (−3.12).

Better: 31.Bg1 prepares Rxe4 and Kf2. Engine line: 31…Rh1 32.Rxe4 fxe4 33.Bxh1 Qxh1 34.Kf2 (−3.12).

35…Rxg1 is a mistake: Black's winning chances go from 100% to 88%.

• White answers 36.Qxg1, which takes the rook on g1.
• After Qxg1, White wins 5 points of material within 2 moves.
• Better was 35…d4 (−14.74): the pawn kicks the rook on c3, which has to move.

Better: 35…d4 wins a bishop for a pawn, picking it up with 38…Qxh2+, and threatens …Qh2+, winning a rook for a pawn, picking it up with 37…Qxg1+. After 36.Qf1 e3+ 37.Rxe3 Rh2+ 38.Bxh2 Qxh2+ 39.Ke1 dxe3 40.Rb2 Qxg3+ 41.Kd1, Black comes out a piece up (−14.74).

36…d4! The only good move here: every alternative is clearly worse.

• Attacks the rook on c3, which is undefended.
• Takes e3 away from the rook on c3.
• The next best move, 36…e3+, would drop Black's winning chances from 89% to 67% (−1.87).
• 36…d4 wins a rook for a pawn, picking it up with 37…dxe3+.
• Sets up a sequence and wins a rook for a pawn once the captures settle, picking it up with 37…dxe3+.
• White answers 37.Re3, leaving Black with an isolated pawn on e4.

45…Re6 is a mistake: Black's winning chances go from 93% to 76%.

• White answers 46.Qd2.
• Better was 45…Rxe5 (−6.97), which takes the pawn on e5.

Better: 45…Rxe5 wins two pawns and threatens …Qe3#, with mate in 1. After 46.Rd6+ Re6 47.Rxe6+ Bxe6 48.Qd8 Qxb4+ 49.Ke3, the rooks are traded and Black comes out two pawns up (−6.97).

46.e4 is a mistake: White's winning chances go from 24% to 7%.

• Black answers 46…Bd3: adds a attacker on the e4 pawn: 2 attackers against 2 defenders.
• Better was 46.Qd2 (−3.20).

Better: 46.Qd2 threatens Qxc3, winning the queen for a rook, and stops the mate threat …Bxe2. After 46…Qa1 47.Qd1 Qxd1 48.Rxd1 Bxe2 49.Rd8, the queens come off and White is a pawn down (−3.20).

46…Qf3+ is a blunder: Black's winning chances go from 93% to 9%.

• White answers 47.Qxf3, which takes the queen on f3.
• After Qxf3, White wins 4 points of material within 6 moves.
• Better was 46…Bd3 (−7.18): adds a attacker on the e4 pawn: 2 attackers against 2 defenders.

Better: 46…Bd3 stops exf5+. After 47.Rxd3 Qxe5+ 48.Ke3 Qxg3+ 49.Kd2 Qxd3+ 50.Kxd3 Rd6+, Black is the exchange plus a pawn down (−7.18).

• Both sides followed opening theory up to 4…b5: 8 moves in all, 4 by White and 4 by Black.
• Theory runs out after 4…b5: too few games between strong players reached this position to go further.