| Sep-28-22 | | Brenin: OTB one wouldn't bother with much calculation: 21 ... Rxf4 22 exf4 Nf5 is an obvious way of exploiting White's dark square weaknesses, caused by the disastrous choice to recapture with the g-pawn rather than the Q on move 20. |
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| Sep-28-22 | | jrredfield: The key is for Black to remove the protection of White's d-pawn and leave White with doubled isolated pawns, shredding White's pawn structure. So 21 ... Rxf4 and Black controls the center. My analysis with the engine shows that any other move for Black leads to a draw at best. (e.g. Nf5, Nc6, d5) |
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| Sep-28-22 | | Cheapo by the Dozen: It's obvious that the game line recaptures the sacrificed Exchange with positional advantage, due to the threats of bishop and knight forks. Calculating all paths to victory is much harder, but fortunately not really needed. |
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| Sep-28-22 | | mel gibson: I didn't see that.
Stockfish 15 agrees with only the first ply
and takes a different line:
21... Rxf4
(21. .. Rxf4 (♖f8xf4 ♔g1-h2 ♖f4-f6 ♕d1-c1 ♖b8-c8 f3-f4
♔h7-h8 ♗b3-c2 d6-d5 ♖f1-g1 c7-c5 d4xc5 ♖c8xc5 ♕c1-d2 ♖c5-c7 ♖a7-a3 ♕d8-f8
♗c2-b1 ♖c7-d7 ♖g1-g4 ♖d7-d8 ♖a3-d3 ♖d8-e8 ♖d3-a3 ♖f6-e6 ♖g4-g3 ♘e7-f5
♗b1xf5 ♕f8xf5 ♕d2-d3 ♕f5xd3 ♖a3xd3 ♖e8-d8 h3-h4 b5-b4 h4-h5 g6-g5 f4xg5
♗g7-e5 ♔h2-g2 ♗e5xg3 ♔g2xg3 h6xg5) +7.16/44 725) score for Black +7.16 depth 44. |
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Sep-28-22
 | | An Englishman: Good Evening: Sacrifice first, analyze later. After Black's move, one doesn't need a forced win to love the ensuing position. |
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| Sep-28-22 | | agb2002: White threatens Ne6.
This threat suggests 21... Rxf4 22.exf4 Nf5:
A) 23.Ra1 Bxd4+
A.1) 24.Kh2 Qh4
A.1.a) 25.Qe1 Qxf4+ 26.Kh1 (or 26.Kg2 Ne3+) 26... Ng3+ 27.Kg2 Nxf1 wins two pawns at least. A.1.b) 25.Qd2 Qg3+ 26.Kh1 Qxh3+ 27.Qh2 Ng3#.
A.2) 24.Kg2 Ne3+ and 25... Nxd1 wins decisive material. A.3) 24.Kh1 Qh4 25.Qd2 (or 25.Kg2 Qg3+ 26.Kh1 Qxh3#) 25... Qxh3+ 26.Qh2 Ng3#. A.4) 24.Rf2 Qh4
A.4.a) 25.Qf1 Qg3+ 26.Qg2 (26.Kh1 Bxf2 wins decisive material) 26... Bxf2+ wins decisive material (27.Kf1 Ne3+). A.4.b) 25.Qe1 Qg3+ 26.Kf1 Qxh3+ 27.Rg2 (27.Ke2 Re8+ wins) 27... Qxf3+ 28.Rf2 Ng3+ 29.Kg1 Qh1#. B) 23.Kh2 Bxd4 looks similar to A. |
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| Sep-28-22 | | saturn2: The first two moves should get back the exchange because Bxd4 and Ne3 are in the air. So black will be two pawns up. |
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| Sep-28-22 | | mayankk06: The exchange sac Rxf4 is quite obvious as it messes up White's already weak pawn structure and creates multiple targets in f4 and d4 pawns. The only confusion I had was if I should start with 21... Nc6 first, push away the a7 Rook and then after 22... Rxf4 23 exf4, continue with 23... Bxd4+ and 24... Qh4. The advantage of this line versus 21... Rxf4 22 exf4 Nf5 was that White has no free move. However the Black Knight is far away from action on c6 square instead of f5. |
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| Sep-28-22 | | TheaN: Agreeing with <Brenin> as per usual, this is one of those lines where you play it, no matter if it's objectively best. After <21....Rxf4 22.exf4 Nf5 -+>:
click for larger view
What did Black achieve? Pd4 is going to fall threatening to win a rook back. The f-pawns are not moving unless White gives the exchange back forcefully. Black moved the knight, obviously, also threatening Qh4 with Qxh3 and Qg3+ looming. In fact, the combination of the above pretty much loses Pd4 and Pf4 by force, given White will first have to counter the check on the g1-a7 diagonal, then Qh4 follows, after which White will have to prevent the queen from entering. This is won, and White can only make it worse. |
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| Sep-28-22 | | TheaN: <Brenin: caused by the disastrous choice to recapture with the g-pawn rather than the Q on move 20.> This is one of these, "the theory looks way better than the (short term) practice". White was probably not liking 20.Qxf3 Nxd4, but it doesn't take too long to see that after 21.Qd1 ⩲ Black's the one with the weak squares and won't enjoy the pawn advantage for long. Her best there would be to simplify with 21....Ra8 22.Rxa8 Qxa8, and now White's best is 23.Bxd4 Rxf4 24.Bxg7 Kxg7 25.Qc1, winning c7 back, 25....Rd4 26.Qxc7 ⩲:
click for larger view
and White's slightly better. Probably not in theory, but Black's position doesn't play easily. Instead, she probably pictured options after 20.gxf3? like Kh2 with Rg1, and in case of 20....Nxe3 21.fxe3 restoring pawn structure... highly doubt she considered the hit on f4 at all. |
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Sep-28-22
 | | chrisowen: It's makers jodhpur Rxf4 abled it's leeway key duh it's axiom jug its charger Rxf4 ebb; |
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| Sep-28-22 | | Refused: 21...Rxf4 22.exf4 Nf5 -+ white is simply to weak on the dark squares. Black's threatening 23...Bxd4+24...Bxa7, 23...Ne3 would be an emergency exit if black gets scared. The threat of Qh4 is in the air. It's just too many holes to plug. |
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Kibitzing
sac: 21...Rxf4