Praggnanandhaa R vs Hikaru Nakamura: game review

18…Nce4!! A real sacrifice: Black gives up material and the engine still rates it best.

• Leaves the rook on f8 where it can be taken.
• White can take, but after 19.Bxf8 Kxf8 20.N5h4 Ng4 the engine rates it +0.14.
• The knight joins the attack: it now hits 2 squares around the White king.
• Moves the attacked knight to safety.
• 18…Nce4 gets the knight out of the way of dxc5.
• White was threatening dxc5, winning a knight. The knight steps away.

• The idea: 18…Nce4!! gives up the rook on f8 to stay in the game: after it Black holds the balance (+0.14); anything else leaves Black clearly worse (+2.68).
• What Black gives up: 18…Nce4 leaves the rook on f8 hanging to the bishop on a3. That's a whole rook on offer.
• What it does instead: It threatens …Qxf5, winning a knight for a rook.
• If White takes the rook: 19.Bxf8 is met by 19…Kxf8, taking the bishop on f8 and threatening …Qxf5, winning a knight. Then 20…Ng4 threatens …Ngxf2, winning a pawn, and 21…g5 threatens …gxh4, winning a knight. Black ends up a pawn ahead: Black holds the balance (+0.17). This is White's best try.
• Without the sacrifice: The best move without the sacrifice, 18…Nfe4, is clearly weaker (+2.68 against +0.14). White answers 19.g4, pushing the pawn storm towards the king. That would leave Black clearly worse.

21.Qxf5! The only good move here: every alternative is clearly worse.

• Takes the queen on f5.
• The next best move, 21.Ne1, would drop White's winning chances from 68% to 39% (−1.19).
• 21.Qxf5 trades off the attacked queen instead of losing it to …Qxc2 and trades queens.
• Black was threatening …Qxc2, winning the queen. The queen takes something with it instead.
• Trades queens: the queens come off while ahead, which makes the extra material easier to convert.
• The queen on f5 can be taken by the knight on g3.

41…Ra1 is a mistake: Black's winning chances go from 42% to 26%.

• White answers 42.Rb6+: the rook joins the attack: it now hits 2 squares around the Black king.
• After Rb6+, White wins 1 point of material within 4 moves.
• Better was 41…Kd6 (+0.84), which attacks the rook on c7, which is undefended.

Better: 41…Kd6 threatens …Kxc7, winning a rook, and stops Rb6+. Engine line: 42.Rc8 Kd7 43.Rf8 Ke7 44.Rh8 Ra6 (+0.84).

42.Rb6+! The only good move here: every alternative is clearly worse.

• The rook joins the attack: it now hits 2 squares around the Black king.
• Gives check, so the reply is forced.
• The next best move, 42.Kg2, would drop White's winning chances from 74% to 59% (+1.00).
• 42.Rb6+ wins a pawn, picking it up with 43.Rxf6.
• Sets up a sequence and wins a pawn once the captures settle, picking it up with 43.Rxf6.
• Black answers 42…Kd5.

44.e4+! The only good move here: every alternative is clearly worse.

• Check, and Black has only one legal reply.
• The next best move, 44.hxg5, would drop White's winning chances from 84% to 69% (+2.17).
• 44.e4+ wins a pawn, picking it up with 45.hxg5.
• Sets up a sequence and wins a pawn once the captures settle, picking it up with 45.hxg5.
• Black answers 44…Kg6, leaving White with a king with pawns missing from its shelter.
• Engine line: 44…Kg6 45.hxg5 Rg1+ 46.Kf2 Rxg5 47.Rb8 (+4.30).

45.hxg5! The only good move here: every alternative is clearly worse.

• Takes the pawn on g5.
• Leaves Black with an isolated pawn on h5: a long-term weakness.
• The next best move, 45.Rbb7, would drop White's winning chances from 86% to 50% (+0.04).
• 45.hxg5 stops …gxh4+.
• Black was threatening …gxh4+, winning a pawn. hxg5 takes care of it.
• Takes the g5 pawn.

50.Rh7+ misses 50.f4, which wins material. White's winning chances go from 99% to 89%.

• Black answers 50…Kg5, which attacks the rook on f6, which is undefended.
• Better was 50.f4 (+11.82), which pushes the passed pawn to f4.

Better: 50.f4 wins a rook for a pawn, picking it up with 52.fxe5, and threatens Rg5#, with mate in 1. After 50…Ra5 51.e5 Rxe5+ 52.fxe5 Nb4 53.Ke4, White comes out a piece and a pawn up (+11.82).

55.f4 misses the chance 54…Ne1 gave: 55.Rfg7+ would have punished it. White's winning chances go from 96% to 83%.

• Black answers 55…Nf3+, which gives check, so the reply is forced.
• Better was 55.Rfg7+ (+8.92): the rook takes the open g-file.

Better: 55.Rfg7+ takes the open g-file. Engine line: 55…Kf6 56.e5+ Kf5 57.Rf7+ Kg5 58.Ke4 (+8.92).

• Both sides followed opening theory up to 7…Nbd7: 14 moves in all, 7 by White and 7 by Black.
• Theory runs out after 7…Nbd7: too few games between strong players reached this position to go further.