< Earlier Kibitzing · PAGE 2 OF 2 ·
|May-07-17|| ||morfishine: I got the first & second moves but not the next 24|
|May-07-17|| ||Walter Glattke: Yes, no compensation for the bishop sac.|
|May-07-17|| ||RandomVisitor: After 22.Bxf8
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Komodo-10.1-64bit: <3 1/2 hours computer time, Selectivity 70>
<+0.68/44 22...gxh4 23.Bxc5 Bf5 24.Re7 Qg6 25.Bxf5 Qxf5 26.h3 Qc2> 27.Rxc7 Qxb2 28.Bd4 Re8 29.Rxc6 Qd2 30.Rg6+ Kf7 31.Rf6+ Ke7 32.Rb1 Qxd4 33.Rf7+ Kxf7 34.cxd4 Kf6 35.Rb5 Re1+ 36.Kh2 Re2 37.Rxd5 Rxa2 38.f3 Ra4 39.Rd6+ Kg5 40.Rd8 Rb4 41.Rd7 a5 42.Rd5+ Kg6 43.Rxa5 Rxd4 44.Ra8 Kg5 45.Rg8+ Kh5 46.Rg4 Rd7 47.Ra4 Rd2 48.Re4 Rc2 49.Rd4 Ra2 50.Rd5+ Kg6 51.Rd4
|May-07-17|| ||Iwer Sonsch: <RandomVisitor> Stockfish 7 agrees - <26...Qc2! 27.Rxc7 Qxb2 28.Bd4 c5> 29.Rxc5 Qxa2 30.Re1 is being rated 0.67 @depth 36. I selected 28...c5 before Stockfish rated it like this, but other moves seem relatively equal.|
Komodo is impressive.
|May-07-17|| ||Walter Glattke: I see, the computers proofed move 27, but what would they say to 23.-Be6 instead of Bf5 . 24.Re3!? Re8 would stop Re7 and Bd4 then.|
|May-07-17|| ||RandomVisitor: <Iwer Sonsch>Stockfish and Komodo are about equally strong, with Stockfish a few ELO points higher, I think.|
|May-07-17|| ||RandomVisitor: <Walter Glattke>23...Be6 perhaps 24.Re5! Qf6 25.Rfe1 Bd7 26.h3 a5 etc with white advantage.|
|May-07-17|| ||RandomVisitor: After 22.Bxf8 Komodo 10.1
<+0.58/45 22...gxh4 23.Bxc5 Bf5 24.Re7 Qg6 25.Bxf5 Qxf5 26.h3 Qc2> 27.Rxc7 Qxb2 28.Bd4 Re8 29.Rxc6 Qd2 30.Rg6+ Kf7 31.Rf6+ Ke7 32.Rc6 Kd7 33.Ra6 Re1 34.Rxa7+ Ke8 35.Rxe1+ Qxe1+ 36.Kh2 Qe4 37.Rg7 Qf4+ 38.g3 hxg3+ 39.Rxg3 h5 40.Kg1 Qd2 41.Rg8+ Kf7 42.Rg7+ Ke8 43.Kh2 Qxa2 44.Rg5 Qd2 45.Rxh5 Qf4+ 46.Kg1 Qf3 47.Re5+ Kd7 48.Re3 Qf5 49.Rg3 Kc6 50.Rg4 Qf3 51.Kh2 Kd7 52.Rg3 Qf4 53.Kg1 Qe4
|May-07-17|| ||Walter Glattke: I see now 23.-Be6? 24.Re5 a6 25.Rfe1 Re8
26.Bf5! wins, and 24.-Re8 25.Rfe1 Bd7
26.Rxe8+ Bxe8 27.Re7 brings Qh5 or
24.-Re8 25.Bxa7 Ra8 26.Bc5 Rxa2 27.Rfe1
|May-07-17|| ||Walter Glattke: For the not so strong kibitzers: White wins with 23.-Ba6? 24.Re7 Bxf1 25.Rxf7 Kxf7 26.Kxf1 ... but it lasts longer.|
|May-07-17|| ||morfishine: Black's best chance to draw after the puzzle position was 24.Re7 <24...Qxe7>
25.Bxe7 Bxc2 26.Bxh4 Bf5
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True, White has 3-1 pawn superiority on the King side, but Black has a pawn superiority on the Q-side and can try to take advantage of opposite colored Bishops in the long run
|May-07-17|| ||scholes: <RandomVisitor> Latest stockfish dev is more than 50 elo stroger than Komodo 10.1.
You can get latest from here
|May-07-17|| ||patzer2: Calculating a combination like today's Sunday puzzle (22. ?) was more difficult back in my early playing days when Chess books (what we used for Chess study before the internet) said a Queen was worth 10 pawns.|
With the modern accurate assessment of a Queen's value at 9 pawns, it wasn't so hard to figure out that the exchange 22. Bxf8! gxh4 23. Bxc5 to with a Rook (5 points), a Bishop (3 points), two isolated Black pawns and an exposed Black King for a Queen for her majesty was "priceless" (a reference to the USA Mastercard commercials such as the one at https://www.youtube.com/watch?v=QJU....)
The only viable alternative was passively giving up the piece for two pawns with 22. Qxh6 Bxe7 23. Qxc6 Rb8 24. Bb3 Rxb3! 25. axb3 Bd6 26. Rd1 Be6 (-0.65 @ 21 depth, Deep Fritz 15) when (diagram below)
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Black's two extra Bishops for the Rook give the second player the stronger position despite the minus one material count.
Not only is such a position more difficult for White, it is much less fun than the game continuation. Moreover, such boredom would certainly not be allowed by our chessgame.com site sponsor as worthy of a Sunday puzzle.
|May-07-17|| ||patzer2: Looking at objectively, it's not at all clear that the boring 22. Qxh6 alternative isn't any less likely to fizzle out to a draw than than the fun and exciting 22. Bxf8! line. Calculating it with Stockfish 8 to a mere 35 depth gives evaluations for these top two lines with no clear decisive result for either of them:|
( [Stockfish 8 64] 35:+0.36 22.Bxf8 gxh4 23.Bxc5 Bf5 24.Re7 Qg6 25.Bxf5 Qxf5 26.h3 Qc2 27.Rxc7 Qxb2 28.Bd4 c5 29.Rxc5 Qxa2 30.Rc7 Rb8 31.Rxa7 Qc2 32.Rg7+ Kf8 33.Kh2 Rb1 34.Rxb1 Qxb1 35.Rg4 Qb8+ 36.f4 h5 37.Rxh4 Qe8 38.Be5 Qg6 39.f5 Qe8 40.Bg3 Qc8 41.Rxh5 Qxc3 42.Rh4 Qf6 43.Rf4 Ke7 )
( [Stockfish 8 64] 35:-0.85 22.Qxh6 Bxe7 23.Qxc6 Rb8 24.Bb3 Rxb3 25.axb3 Bd6 26.Re3 Bd7 27.Qb7 Qf5 28.Rf3 Qe5 29.Rxf8+ Kxf8 30.g3 Bc5 31.Qa6 Kg7 32.Qd3 Bg4 33.b4 Bb6 34.b5 Kh6 35.Kg2 Qe6 36.Kg1 Bf5 37.Qd2 Kh5 38.Re1 Be4 39.c4 Qf5 40.Qe2+ Kg6 41.g4 Qf3 42.Qxf3 Bxf3 43.b3 Kf6 44.cxd5 Bxg4 45.b4 )
|May-07-17|| ||Iwer Sonsch: <patzer2: <giving up a Piece for two pawns>> Actually, White can force to get three (24.Bg6!?), which made it really hard to find out that the combination was bad for White.|
Like I already said, the game line was easy to spot, but difficult to acknowledge as the best. Therefore, today's puzzle was a marvellous spoiler of Sunday difficulty.
|May-07-17|| ||Iwer Sonsch: <morfishine> Great move you discovered! As we see, you can't always trust the computers when they give one line with the best moves.|
After 24...Qxe7! 25.Bxe7 Bxc2 26.Bxh4 (without 26...Bf5), Stockfish rates the position 0.74 @depth 33, a number that is way more equal with two different coloured bishops than in the unsymmetrical line after 26...Qc2.
|May-07-17|| ||morfishine: <Iwer Sonsch> Thanks for looking, its good to see SF has it at less than 1-pawn advantage|
And welcome to <CG>!
|May-07-17|| ||patzer2: <Iwer Sosch> I agree. My criteria for picking the game line for my solution was simply that it was more fun and exciting. Since chessgames.com Sunday puzzle solutions tend to favor entertaining lines, I figured that must be the answer.|
Until I plugged it into Stockfish 8 for a deep look, I had only an inkling that positions like the one in my second post above (with a calculated one plus pawn advantage for White) actually slightly favored Black.
|May-07-17|| ||agb2002: The material is identical.
Black threatens gxh4 and Bxe7.
White has Qxh6, Bxg5 and Bxf8.
After 22.Bxg5 hxg5 23.Qxg5+ Qg7 the attack seems to vanish.
In the case of 22.Bxf8 gxh4 23.Bxc5 Bf5 it's not clear that White has compensation.
In the case of 22.Qxh6 Bxe7 23.Qxc6 followed by Bb3 (exerting pressure on c7 and d5) looks more promising than the alternatives.
That's all I'll do today.
|May-07-17|| ||Walter Glattke: To patzer 2, if BN:RP or QP:RR would not
work, the chess would break intogether by manipulations. Prof. Euwe said, a rook is 5,5, but this is all very tricky, it could work only under "gambit tension" with additional tactical effects.
|May-07-17|| ||patzer2: <Walter Glattke> One of my favorite Emanuel Lasker quotes can be found at http://www.azquotes.com/author/2391...|
"By positional play a master tires to prove and exploit true values, whereas by combinations he seeks to refute false values...A combination produces an unexpected re-assessment of values."
Perhaps there's a corollary to Lasker's aphorism about the value of the pieces being reassessed in a combination. That truth being that the value of the pieces also requires reassessment in positions clearly more favorable for advantageous tactical play by one side.
|May-07-17|| ||patzer2: Letting Stockfish 8 run for over five hours calculating today's Sunday puzzle (22. ?) to 45 depth, it turns out the silicon monster finds 22. Bxf8! to significantly better (precisely 1.66 pawns better) than 22. Qxh6 Bxe7 :|
( [Stockfish 8 64] 45:+0.74 22.Bxf8 gxh4 23.Bxc5 Bf5 24.Re7 Qg6 25.Bxf5 Qxf5 26.h3 Qc2 27.Rxc7 Qxb2 28.Bd4 c5 29.Rxc5 Re8 30.Rc6 Qd2 31.Rg6+ Kf7 32.Rf6+ Kg7 33.Rb1 Qxd4 34.cxd4 Kxf6 35.Rb5 Re1+ 36.Kh2 Re2 37.a3 Ke6 38.f3 Rd2 39.Rb4 Kf6 40.Ra4 Kg5 41.Rxa7 Rxd4 42.Rd7 Kf6 43.Rd6+ Kg7 44.Kg1 Rd3 45.a4 Ra3 46.Rxd5 Rxa4 47.Kf1 Kf6 48.Rd6+ Kg5 to )
( [Stockfish 8 64] 45:-0.92 22.Qxh6 Bxe7 23.Qxc6 Rb8 24.Bb3 Rxb3 25.axb3 Bd6 26.Re3 Bd7 27.Qb7 Qf5 28.Qxa7 Bb5 29.Rf3 Bf4 30.Re1 g4 31.Rg3 Bd7 32.Qd4 Bxg3 33.hxg3 Rf6 34.b4 c6 35.b3 Re6 36.Rxe6 Qxe6 37.Kf1 Kf7 38.c4 Qf5 39.b5 cxb5 40.cxd5 Qb1+ 41.Ke2 Qa2+ 42.Ke1 Bf5 43.b4 Qc4 44.Qxc4 bxc4 45.Kd2 Be4 46.d6 Ke6 47.d7 Kxd7 48.Kc3 Bxg2 )
|May-07-17|| ||patzer2: For a Black improvement, instead of 19...h6 the second player can keep it level and less complicated with 19...Bf5 when play might continue 20. Be3 Bb6 21. Bxf5 Qxf5 22. Rae1 Rae8 23. Bxb6 cxb6 24. Re7 Qc2 25. Rxa7 Qxb2 26. Qd4 Rg8 = (0.16 @ 24 depth, Deep Fritz 15)|
|May-07-17|| ||RandomVisitor: After 26.h3
click for larger view
Komodo-10.1-64bit: <3 1/2 hours computer time>
+0.64/34 26...Qc2 27.Rxc7 Re8 28.Rxc6 Qxb2 29.Bd4 Qd2 30.Kh2 Qf4+ 31.Kh1 Qd2 32.Rg6+ Kf7 33.Rf6+ Kg7 34.Rf4+ Kg6 35.Rxh4 h5 36.g4 hxg4 37.Rxg4+ Kh5 38.Kh2 a5 39.a4 Re2 40.Rfg1 Re1 41.Rxe1 Qxe1 42.Rg8 Qe4 43.Rh8+ Kg5 44.Rf8 Kh5 45.Rf7 Qc2 46.Rf6 Qe4 47.Kg3 Qh4+ 48.Kg2 Qe4+ 49.Kh2
+1.26/34 26...Rc8 27.b4 a5 28.a3 Qf6 29.Re3 Qg6 30.bxa5 Qc2 31.a6 Qa4 32.a7 Qa5 33.Rfe1 Qxc5 34.Re8+ Kf7 35.Rxc8 Qxa7 36.a4 Qa5 37.Re3 Qa7 38.Rh8 Kg7 39.Rhe8 Qxa4 40.R8e7+ Kg6 41.Re1 Kf6 42.Rxc7 Qc4 43.Re3 Qa6 44.Rh7 Kg6 45.Rhe7 Qa1+ 46.Kh2 Qa4 47.Rd7 h5 48.Rd6+ Kg7 49.Rde6 c5 50.R6e5 Qc4
+1.51/34 26...Rb8 27.Rfe1 d4 28.R7e5 Qc2 29.R5e2 Qf5 30.cxd4 a5 31.Re4 Kh7 32.Re7+ Kh8 33.Rxc7 Rc8 34.Rce7 Rd8 35.R7e6 Kh7 36.R6e5 Qc2 37.Re7+ Kg8 38.R7e2 Qf5 39.Re4 Kh7 40.Rxh4 Rg8 41.Bd6 Rg6 42.Re7+ Kg8 43.Re8+ Kg7 44.Rhe4 Rxd6 45.R4e7+ Kg6 46.Rg8+ Kf6 47.Rf8+ Kxe7 48.Rxf5 Rxd4 49.Re5+ Kd7 50.Rxa5 Rd1+ 51.Kh2 Rd2 52.b3 Rxf2 53.Kg3
|May-08-17|| ||patzer2: The potentially game saving and best move 26...Qc2!, attempting to salvage a draw from an inferior position for Black, seems at first anti-positional in leaving the unprotected King stripped of all his defenders.|
Attempting to protect the King and start a potential counter attack with 26...Rf8? at a glance might seem like a good idea.
However, upon closer examination of the position after 26...Rf8?, it turns out that White cannot stop Black from posting a Bishop on d4 and successfully harassing the Black King with discovered check to likely win decisive material. Also, leaving the Black Queen on f5 leaves her exposed to capture via a discovered attack.
So instead of 26...Rf8? allowing 27. Re1 to (+2.02 @ 32 depth, Stockfish 8), Black is much better off with the strange looking 26...Qc2 to (+0.64 @ 34 depth, Komodo 10.1 as in RV's analysis posted above.)
Positionally, 26...Qc2! accomplishes several goals:
(1) Without being impeded by his own pieces, it allows the Black King more freedom to roam and escape combined Rook and Bishop checks after White's coming Bd4.
(2) It hides the Queen from a potentially disastrous discovered check by the Black Bishop and Rook.
(3) It allows Black enough time to win the pawn on b2 and create some potential Queen-side passed pawn counter threats, so that White cannot win easily by simplifying to a won King and Pawn endgame.
P.S.: All that being said, it's still possible a strong player or computer program might find a win after 26...Qc2! However 26...Qc2! would have made it extremely difficult for White to win. Instead, 26...Rf8? 27. Re1 to made it highly likely the lower rated player in this game would pull off the upset.
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