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Later Kibitzing> |
Dec-11-18
 | | agb2002: White is a pawn ahead.
Black threatens Bxf2.
The bishop on e1 x-rays its black counterpart on h4. Hence, 26.Rxf8+: A) 26... Rxf8 27.Rxf8+ Qxf8 (27... Kxf8 28.Qxh4 + - [B+N+P vs r]) 28.Qxh4 Qf4 29.Qg3 + - [B+N+P vs r], Black doesn't have counterchances. B) 26... Kg7 27.R2f7+ wins decisive material. |
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| Dec-11-18 | | saturn2: White has a pawn more.
26. Rxf8+ Rxf8 27. Rxf8+ Rxf8 28. Qxh4
White has also a piece more. |
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| Dec-11-18 | | mel gibson: I wasn't sure.
I was looking for a checkmate but in the end
it was just a piece swapping exercise.
Stockfish 10 says:
26. Qxh4
(26. Qxh4 (♕h3xh4 ♕e7xh4 ♖f3xf8+ ♖d8xf8 ♖f2xf8+ ♔g8xf8 ♗e1xh4 ♔f8-f7
♗h4-g5 a7-a5 ♔g1-f2 ♖c8-a8 ♘d2-f3 a5-a4 a2-a3 ♗b5-c4 ♗g5-f6 ♖a8-a6 ♔f2-e3
♔f7-g8 ♗f6-e7 ♗c4-b3 ♗c2xb3 a4xb3 ♗e7-d6 h7-h6 ♘f3-d2 b7-b6 ♘d2xb3 ♔g8-f7
h2-h4 ♖a6-a8 ♘b3-c1 ♔f7-e8 b2-b3 ♔e8-d7 ♘c1-e2 b6-b5 h4-h5 g6xh5 g4xh5
♖a8-a6) +5.14/35)
score for White +5.14 depth 35. |
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| Dec-11-18 | | Cheapo by the Dozen: White starts out up a pawn. So getting two pieces for the rook while simplifying leads to a clearly winning position. The engine says that Black was not premature in resigning. |
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| Dec-11-18 | | Cheapo by the Dozen: RxN+ at f8 was a theme for a long stretch of the game, starting when White's knight was first apparently hanging at e5. |
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| Dec-11-18 | | AlicesKnight: I went with <ChessHigherCat>'s line. After 28 ...Q any; 29.Bf6 and White brings up reserves. In the game line the same threat of Bf6 embarrasses the R. |
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| Dec-11-18 | | saturn2: <An Englishman> If black takes the knight white wins back a piece soon or gets a mating attack. 13...fxe5
14. fxe5 (Bh4 is not necessary) Bc7
15. Rxf8+ Kxf8
16. Rf1+ |
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| Dec-11-18 | | malt: Gone for 26.R:f8+
(26.Q:h4 Q:h4 27.R:f8+ R:f8 28.R:f8+ R:f8 29.B:h4 )26...R:f8 27.R:f8+ R:f8 28.B:h4 |
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| Dec-11-18 | | goodevans: <An Englishman: ... Black had multiple opportunities to win the Ne5 and passed on all of them. Did that Knight remain poisoned every single time?> Thanks for pointing this out. It's indeed very interesting. I'd say the soundness of the N-sac is clear to start with since after <13...fxe5 14.fxe5 g6 (14...Bc7?? 15.Rxf8+) 15.Qh3> white will either win the Bd6 or the exchange (via 16.Bh4). Either way black's pieces are in disarray and he's clearly worse. The longer the N sits there, the less obvious the soundness of the attack becomes. Having looked a long time at this, I don't see white recovering the sac'd material quickly after either <15...fxe5> or <16...fxe5>. I think that at this point both players might just 'believe' in the soundness of the sac based on how poorly placed black is to defend white's attack, particularly with the blockage caused by the pawn on e5. |
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Dec-11-18
 | | Dionysius1: Has the database run out of puzzles with more conclusive results <cg>? I don't want to find the solution and be left thinking "but surely there's something better than a clever forced trade to a better endgame". Particularly at the beginning of the week! |
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| Dec-11-18 | | Marmot PFL: 25...Bh4 is a mistake and even 26 Rxf8+ wins easily. |
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Dec-11-18
 | | gawain: I found the right line but wondered whether it was decisive enough. I guess so. |
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| Dec-11-18 | | Chizoad: I went with the forcing line that starts with Qxh4: 26. Qxh4 Qxh4
27. Rxf8+ Rxf8
28. Rxf8+ Rxf8
29. Bxh4
Other move orders work, starting with Rxf8+ and then playing Qxh4. I don't think it matters. Although this sort of rook vs. minor pieces position might not "feel" normal in terms of evaluation, it is so clearly winning for white that Black can easily mash the resign button twice and call it a day. Once white plays Bf6 it will be a miserable experience for black for the remainder of the game. Black is confined to shuffling his pieces and king inside a ever-constricting coffin as white simply keeps improving the position. |
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| Dec-11-18 | | et1: I went for the Easy line but at the end was not sure at all if it was enough. . |
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| Dec-11-18 | | whiteshark: takes, takes +, takes +, takes and win |
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| Dec-11-18 | | Saniyat24: What a position...! :O |
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Dec-11-18
 | | PawnSac: < ChessHigherCat: Some thong tu remember me by! > clever! I like it! If you shorten it to "Some thong tu remember"
you could submit it as a good pun. CG prefers briefness |
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Dec-11-18
 | | patzer2: All roads lead to Rome, and there's more than one way to skin a cat. In this case, there's more than one solution to today's Tuesday (26. ?) puzzle. So my attempt 26. Rxf8+ +- (+4.03 @ 35 ply, Stockfish 9) is just as good as the game continuation 26. Qxh4 (+4.05 @ 31 ply, Stockfish 9). For a Black improvement, I like 14...Ne7 = to ⩱ (-0.26 @ 24 ply, Stockfish 9) better than 14...Be7 15. Raf1 ⩲ to ± (+0.37 @ 25 ply, Stockfish 9). |
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| Dec-11-18 | | TheaN: Tuesday 11 December 2018
<26.?>
There's something unappealing to exchanging quantity over quality: I guess it's a human trait. We'd prefer something better (Rook) over more of lesser value (two pieces). Especially in Blitz I find it extremely unnerving to go into a B+N vs R ending with so many opportunities of the enemy Rook wreaking havoc. Specifically because the pieces can individually do less, the path to victory is usually long and gruesome. In today's puzzle position the situation is slightly different. First of all it's rapid and the middle game, so White would have enough time to prepare himself for the endgame. Second, White already has a pawn. However, third and not least, Black is seriously threatening 26....Bxf2+, so White HAS to act. <26.Qxh4> whoops. And suddenly Black regrets Bh4. <26....Qxh4> Black's alternatives are grim. <27.Rxf8+ Rxf8 (Kg7 28.R1f7+ Kh6 29.Bxh4 +-) 28.Rxf8 Rxf8 (Kxf8 worse) 29.Bxh4> and White now has three pieces vs a Rook and piece. The only part White probably wants to calculate beforehand is if <29....Rf4> works, as anything else just spells doom for Black, but after <30.h3 +-> Black has no access over the f-file and will eventually lose. Typically, this is exactly what was played OTB and it prompted a rightful resign: Black's Rook is a... shuffling? duck. |
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Dec-11-18
| | PawnSac: After 29. Bxh4
click for larger view29. ..Rf4 is a waste of time. White has control of most of the F file,
so after 30.h3 black is forced to retreat the R. If instead he tries to increase the pressure on the g pawn with something like ..h5 or ..Be8, then Bg5! drives the R back, and if ..h6 to keep the B out of g5 then the g6 pawn falls, OR worse yet, white can play Bf6 trapping the rook behind the pawn phalanx and eventually capture it. So what then does black do? 3 ideas that come to mind. 1. Since white has no Rooks, the open F file is no threat to the black king. As odd as it might seem, he can play Kf7 to bring the K toward the center to support the pawns. 2. There are two open files.. the F and C files. Since the F file is under white control, c8 seems the better square for the R, and.. 3. Black should try to keep the B on an active square, NOT passively placed somewhere like Bd7. Therefore it seems the best try for black is to play ..Rc8 and ..Kf7 and look for ways to create activity on the Q side rather than the move played in the game ( Rf4??) |
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Dec-11-18
| | PawnSac: DIAGRAM 1: After white's 25.Rgf3
click for larger viewThis position is not so simple. White is up a pawn, but after a series of correct exchanges black
might still arrive at a drawn rook and pawn ending. So.. What is black to do? In lieu of a possible
Qg3 and h4 trying to induce Bxd2 winning the 2 bishops, black might try Qg7 vacating the e7 square
for the Bg5. But white is also threatening a4 attacking the LSB.
It would be nice to keep the B eyeing f1, but in lieu of a possible Qside expansion with
a4 Ba6 b4 b6 b5 Bb7 a prophylactic ..b6 (a la Nimzowitsch) might be a good idea.
I don't like the idea of ..Nd7 because of the possibility white might try Rf7 Qx Rx Kx Qxh7+ ...
so I'm stuck with 2 candidate moves ..b6 or ..Qg7 . I'm not sure what else may be good.
Black might play both moves, depending on white's reply. For example..
..b6 Qg3 Qg7 h4 Be7
DIAGRAM 2: White to move after black's dubious 25...Bh4?! 
click for larger viewUh Oh. h4 is a very precarious square for the B. The Be1 immediately suggests white can win 2 minor pieces for the rook with a series of forced moves (checks) as white unloads on f8. The more obvious choice to consider is:
LINE 1: 26.Qxh4! Qxh4 27.Rxf8+ Rxf8 28.Rxf8+ Rxf8 29.Bxh4 DIAGRAM 3: WHITE CAPTURES ON H4 FIRST
click for larger viewThis is the most direct and forcing alternative. But white can also play LINE 2: 26. Rxf8+ Rxf8 27. Rxf8+ exposing the double attack on h4. DIAGRAM 4: WHITE CAPTURES ON F8 FIRST
click for larger viewNow black has to choose between 3 alternatives:
a) ...Qxf8 (diagram 5a)
b) ...Rxf8 (diagram 5b)
c) ...Kxf8 (diagram 5c)
DIAGRAM 5a ..Qxf8:
click for larger viewDIAGRAM 5b ..Rxf8:
click for larger viewDIAGRAM 5c ..Kxf8:
click for larger viewand in each of the above cases (5a thru 5c) white must decide whether 'tis better to capture the Bh4 with the Qh3 or the Be1 So you see, at master level play and above, white will see in the tree of analysis SEVEN lines that must be analyzed. Line 1 is a single (and fairly clear) main branch, but line 2 has 6 branches that require more extensive analysis. Which should he choose? Here's where time control makes a huge difference. In a rapid game i think.. "Line 1 is winning, line 2 is more complicated. It may win with greater margin, even brilliantly, but the clock is ticking and I don't have time to analyze the complexities, so I'll stick with the solid option... Qxh4! |
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Dec-11-18
| | PawnSac:
click for larger view< ChessHigherCat: 26. Rxf8+ Rxf8 27. Rxf8+ Rxf8 (...Qxf8 28. Qxh4 or 28. Bxh4This only wins the exchange but leaves black with major weaknesses
on the dark squares and after 39. Bf6 black's queen is tied down defending his castle. When I played through the game line I thought:
"Damn, I missed it!" but the game line only wins the exchange too.> You didn,t miss a winning line! Your instinct was good. In CLASSICAL time control with time to analyze other branches in the "tree", I might be inclined to chose YOUR option instead of the simpler Qxh4. |
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Dec-12-18
| | PawnSac:
click for larger view< ChessHigherCat: 26. Rxf8+ Rxf8 27. Rxf8+ Rxf8 (...Qxf8 28. Qxh4 or 28. Bxh4 
click for larger view< Walter Glattke: I thought the same as Cat, and
38.-Qf7 39.Bf6 a5 40.Nf3 Bd7 41.Ng5 could follow, seems to be better. > 
click for larger view..Qf7? is not the best square for the Q. c7 or g7 are better, so as not to block the bishop's light square diagonals. Bd7 just self-traps the Queen, and ..a5 lacks a meaningful continuation |
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Dec-12-18
| | PawnSac: Looking at diagram 3 and 4 above, black is probably better to play a) ...Qxf8 (diagram 5a) , but since a couple of you were looking at b) ...Rxf8 (diagram 5b) ...
click for larger viewin this position we see g5? is not possible since after Bxg5 black can't capture the B since Qxh7 is mate. So black must move the Q. It is clear white intends to play Bf6 and will follow with Nf3, from where it has 2 good alternatives.. Ng5 or Nh4. From h4 the N attacks g6 and if hxg6 the white Q has access to h8! Thus from our diagram above, a logical continuation would be ..Qc7 Bf6 Be8 reinforcing the g6 pawn, but white has a strong initiative, so the line following the capture on f8 is promising if one is playing at classical time control. conclusion:
the game variation with Qxh4 as played in the actual game is strong and surely winning, yielding a N + B + p vs. R The game variation with Rxf8 first is also interesting, gives black more opportunity to go wrong, and at longer time control white may have sufficient time to plot the strongest path to a win with additional tactical play. |
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Dec-12-18
| | PawnSac: The line with Qxh4 is clear, simplifies (trades off Qs) and in the interest of rapid time control is easier evaluate. It heads right for the end game. The line with Rxf8 first has more complications, is still a middle game position, and is more suitable for classical time control. |
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Kibitzing
sac: 26.Qxh4