Sina-Movahed vs Hikaru: game review

56…fxg4! The only good move here: every alternative is clearly worse.

• Takes the pawn on g4.
• Pushes a pawn towards the White king, to pry open lines in front of it.
• The next best move, 56…Kg6, would drop Black's winning chances from 50% to 36% (+1.58).
• 56…fxg4 stops Rxf5+.
• White was threatening Rxf5+, winning two pawns. fxg4 takes care of it.
• Trades pawns.

63…Rh3! The only good move here: every alternative is clearly worse.

• The rook takes the half-open h-file.
• The next best move, 63…Rc1, would drop Black's winning chances from 45% to 30% (+2.33).
• 63…Rh3 takes the half-open h-file.
• White answers 64.Rd4+, joining the attack on the king.
• Engine line: 64.Rd4+ Kc8 65.Rde4 Rf6+ 66.Kg1 Rff3 (+0.35).

64…Rcc3! The only good move here: every alternative is clearly worse.

• The rook joins the attack: it now hits 3 squares around the White king.
• Protects the rook on h3, which was hanging.
• The next best move, 64…Rh4, would drop Black's winning chances from 48% to 25% (+2.93).
• 64…Rcc3 stops Kxh3.
• White was threatening Kxh3, winning a rook. Rcc3 takes care of it.
• White answers 65.Kg1.

76.Rxg1! The only good move here: every alternative is clearly worse.

• Takes the rook on g1.
• The next best move, 76.Rd4+, would drop White's winning chances from 85% to 65% (+1.67).
• 76.Rxg1 trades off the attacked rook instead of losing it to …Rxf1+ and trades rooks.
• Black was threatening …Rxf1+, with a dangerous check. The rook takes something with it instead.
• Trades rooks: trading pieces when ahead brings the win closer.
• The rook walks into a pin by the rook on h1.

88.Rf7 is a blunder: White's winning chances go from 50% to 6%.

• Black answers 88…Rxf7, which takes the rook on f7.
• Better was 88.Kh6 (0.00).

Better: 88.Kh6 prepares g6 and Ra6. Engine line: 88…a3 89.g6 a2 90.Ra6 Re2 91.g7 (0.00).

88…Rxf7! The only good move here: every alternative is clearly worse.

• Takes the rook on f7.
• The next best move, 88…a3, would drop Black's winning chances from 94% to 53% (−0.35).
• 88…Rxf7 trades rooks.
• Trades rooks: trading pieces when ahead brings the win closer.
• The rook on f7 can be taken by the king.
• White answers 89.Kxf7, taking back, leaving Black with an isolated pawn on a3.

89…a3! The only good move here: every alternative is clearly worse.

• Pushes the passed pawn to a3, close to promotion.
• The next best move, 89…c5, would drop Black's winning chances from 94% to 71% (−2.48).
• 89…a3 pushes the passed pawn to a3.
• White answers 90.g6, leaving Black with an isolated pawn on a2.
• After 90.g6 a2 91.g7 a1=Q 92.g8=Q Qa2+, the pawn promotes on a1 and the pawn promotes on g8 (−7.24).

90…a2! The only good move here: every alternative is clearly worse.

• Pushes the passed pawn to a2, close to promotion.
• The next best move, 90…c6, would drop Black's winning chances from 92% to 59% (−0.99).
• 90…a2 pushes the passed pawn to a2.
• White answers 91.g7.
• After 91.g7 a1=R 92.g8=Q Rf1+ 93.Kg7 Rg1+, the pawn promotes on a1, the pawn promotes on g8 and Black is a piece and a pawn down (−6.72).

• Both sides followed opening theory up to 6.a4: 11 moves in all, 6 by White and 5 by Black.
• Theory runs out after 6.a4: too few games between strong players reached this position to go further.