Hikaru vs Sina-Movahed: game review

21.Rc6 is a mistake: White's winning chances go from 41% to 26%.

• Black answers 21…a4, which pushes the passed pawn to a4.
• Better was 21.Rfc1 (−0.99): the rook takes the open c-file.

Better: 21.Rfc1 takes the open c-file and protects the rook on c4. After 21…Rxc4 22.Rxc4 f6 23.Bd2 Nb4 24.g4, the rooks are traded (−0.99).

22…Rb5! The only good move here: every alternative is clearly worse.

• Moves the attacked rook to safety.
• Shores up the e5 pawn, which was under as much attack as it had defence (1 against 1).
• The next best move, 22…Rxe4, would drop Black's winning chances from 66% to 55% (−0.56).
• 22…Rb5 gets the rook out of the way of Bxb4.
• White was threatening Bxb4, winning the exchange. The rook steps away.
• White answers 23.Rfc1.

25…Rb3 is a blunder: Black's winning chances go from 77% to 50%.

• White answers 26.Rc6: adds a decisive attacker on the knight on a6: 2 attackers against 1 defender.
• Better was 25…Bf8 (−3.24), which protects the a3 pawn, which was hanging.

Better: 25…Bf8 stops Rxa3. After 26.Kf1 Rbb8 27.Ra1 f6 28.Ke2 Nc7 29.Rxa8 Rxa8 30.Ne1, the rooks are traded (−3.24).

26.h4 misses the chance 25…Rb3 gave: Rc6 would have punished it. White's winning chances go from 50% to 31%.

• Black answers 26…Bf8: shores up the a3 pawn, which was under as much attack as it had defence (1 against 1).
• Moves a pawn from in front of the king, loosening its cover.
• Better was 26.Rc6 (0.00): adds a decisive attacker on the knight on a6: 2 attackers against 1 defender.

Better: 26.Rc6 threatens Rcxa6, winning a knight. After 26…Rb1+ 27.Be1 Bf8 28.Raxa6 Rxa6 29.Rxa6 f5, the rooks are traded and White comes out a piece up (0.00).

27…Rd8 is a mistake: Black's winning chances go from 69% to 49%.

• White answers 28.Be3, which moves the attacked bishop to safety.
• Better was 27…Nc7 (−2.20): moving away uncovers the rook on a8, which now hits the rook on a4.

Better: 27…Nc7 threatens …Rxa4, winning the exchange. After 28.Rxa8 Nxa8 29.Kh2 Nb6 30.Ng4 Bg7, the rooks are traded (−2.20).

30.Ra7 is a mistake: White's winning chances go from 49% to 30%.

• Black answers 30…Rb1+: the rook joins the attack: it now hits 2 squares around the White king.
• After Rb1+, Black wins 1 point of material within 4 moves.
• Better was 30.f4 (−0.10), which pushes a pawn towards the Black king, to pry open lines in front of it.

Better: 30.f4 threatens Ra7, winning a pawn, picking it up with 31.Rxf7+. After 30…a2 31.Ra7 Rb7 32.Rxb7 a1=Q+ 33.Kh2, the pawn promotes on a1 and White is a piece down (−0.10).

30…Rb1+! The only good move here: every alternative is clearly worse.

• The rook joins the attack: it now hits 2 squares around the White king.
• Check, and White has only two legal replies.
• The next best move, 30…Be7, would drop Black's winning chances from 70% to 8% (+6.55).
• 30…Rb1+ wins a pawn, picking it up with 31…Rxf2.
• Sets up a sequence and wins a pawn once the captures settle, picking it up with 31…Rxf2.
• White answers 31.Kh2.

32…Rf4! The only good move here: every alternative is clearly worse.

• The rook forks the knight and the pawn: both can't be saved at once.
• Moves the attacked rook to safety.
• The next best move, 32…Rff1, would drop Black's winning chances from 86% to 72% (−2.51).
• 32…Rf4 wins two pawns, picking it up with 33…Rxg4, and gets the rook out of the way of Nxf2.
• Sets up a sequence and wins two pawns once the captures settle, picking it up with 33…Rxg4.
• White was threatening Nxf2, winning a rook. The rook steps away.

• Both sides followed opening theory up to 13…Rd7: 26 moves in all, 13 by White and 13 by Black.
• Theory runs out after 13…Rd7: too few games between strong players reached this position to go further.