|Oct-19-13|| ||offramp: It had been a week of puzzles based on the long diagonal. The first move today is fairly obvious; white's 24th is very good.|
|Oct-19-13|| ||devere: 21. Rxb2! followed by 22. Bd4! is positionally devastating. No need to waste much time calculating.|
As the game went 24. Nxf5!? was good enough to win, but 24. Qd1! Qa4 25. Nxf5! would have been even better. Black is busted.
|Oct-19-13|| ||waustad: I started out right but black came up with a much different defense than I'd calculated.|
|Oct-19-13|| ||al wazir: I was with white the first two moves; thereafter I wasn't even in the same room. I never dreamed of 23. a3, let alone 23...Nc5 and the rest of the attack.|
But surely black would have done better with 24...Rxf5 25. Qxf5 (25. axb4 Nxd3) Qxd4+.
|Oct-19-13|| ||plumbst: <al wazir> 24...Rxf5 fails to 25 Qg3+|
|Oct-19-13|| ||morfishine: <waustad: I started out right but black came up with a much different defense than I'd calculated> The same for me. I had 21.Rxb2 Qxb2 22.Bd4 Qxa2 23.Nxf5 Kf7 24.Re1 Qxd5 25.Nh6#|
|Oct-19-13|| ||gofer: This position is all about displacement. The black queen can
easily get deflected away from the protection of its king and
once it is on the wrong side of the board white can re-organise
its pieces to make the eventual attack on black's king more
<21 Rxb2 Qxb2>
<22 Bd4 ...>
If black gets greedy its all over.
22 ... Qxa2
23 Nxf5 Rxf5 (Kf7 Qe4 )
24 Qxf5 Qa4
25 Qe6+ Kf8
26 Qxd6+ Ke8
27 Bf6 Nxf6
28 Qxf6 Kd7
29 Qe6+ Kc7
<22 ... Qb4>
So the object of the exchange down has been completed.
Now to find the killer move that will end it all. Not so
easy! So I know I am winning, but I am not sure how to continue...
Wow! I like <23 a3>, but I don't really understand why black
played <23 ... Nc5>? What was wrong with <23 ... Qa4>?
|Oct-19-13|| ||Penguincw: I saw the exchange sacrifice, but was thinking of something like 21.Nh5 to deflect.|
|Oct-19-13|| ||al wazir: <plumbst: 24...Rxf5 fails to 25 Qg3+> You're right. I guess I'm still in the wrong room.|
|Oct-19-13|| ||kevin86: White sucks the black queen into a trap and catches her.|
|Oct-19-13|| ||patzer2: Got 21 Rxb2! Qxb2 22. Bb4 on this Saturday puzzle, but anticipated 22...Qxa2 23. Nxf5 for the continuation.|
The 22...Qb4!? defense and the 23. a3! continuation also surprised me.
|Oct-19-13|| ||devere: To illustrate the strength of the exchange sacrifice, instead of 23. a3 White can simply play 23. Ba1 with a winning position.|
|Oct-19-13|| ||Jimfromprovidence: <patzer2> <The 22...Qb4!? defense and the 23. a3! continuation also surprised me.>|
22...Qb4 attacks the bishop with check, so it stops 23 Nxf5. If 23 Nxf5?, black comes out ahead a piece for a pawn after 23...Rxf5 24 Qxf5 Qxd4+.
|Oct-19-13|| ||Clodhopper: Without a doubt, the difficulty is not finding white's first two moves, but rather finding the next two. I calculated as far as 23 ... Nc5 and thought "this doesn't work". Faced with the position over the board, I would undoubtedly have panicked into a lost end-game.|
|Oct-19-13|| ||devere: <Clodhopper: "Without a doubt, the difficulty is not finding white's first two moves, but rather finding the next two.">|
This exchange sacrifice is so strong, it does not require a precise follow-up.
|Oct-19-13|| ||LoveThatJoker: It says "O'Kelly vs P Dubinin" atop the diagram. I take it this is Alberic O'Kelly de Galway. An interesting note on him: he was the/an arbiter for one of the Petrosian-Spassky matches; (1966) I believe.|
<21. Rxb2 Qxb2 22. Bd4 Qb4>
(22...Qxa2? 23. Nxf5 and even at this point White has tremendous compensation for the exchange as 23...Rxf5 24. Qxf5 ; or 23...Nf6 24. Qg3+ mating; or 23...Kf7 24. Re1 )
The interesting thing is that 22...Qb4! is actually a great defense which should lead to minimal compensation for White after 23. Rb1 Qa4, but maybe Black goes wrong here with:
<23...Nc5 24. Nxf5! Rxf5>
(24...Nxd3? 25. Nh6#)
<25. Qg3+> Black's Queen falls.
PS. I spent a fair bit of time on this puzzle, and all I could find was this cheap trap motif. It should be noted that Black also has the idea 23. Rb1 Qa5, but then 24. Nxf5 is good, as the B is no longer en prise.
|Oct-19-13|| ||LoveThatJoker: Nice, I got it with 23. Rb1 which, imho, is stronger than 23. a3.|
I'll fire up Stockfish to see what is says on this matter. (i.e., whether 23. Rb1 or 23. a3 is best).
|Oct-19-13|| ||Refused: 21.Rxb2 Qxb2 22.Bd4 Qb4 looks like close to curtains. The Black Queen is stranded on the Queen side, while all the white forces will rather sooner than later have a party on the black king side.|
|Oct-19-13|| ||LoveThatJoker: Ok, so Stockfish states that 23. a3 is best but not for reasons which can be called obvious (when attempting to solve the puzzle based on the initial diagram that is).|
23. a3 Qa4 24. Ba1 is the winning idea, says the engine. Man, that's not an easy to move see.
23. Rb1 is still good for White, but less so in that 23...Qa4 24. Re1 is the best that White has - once again, per Stockfish.
After 23. a3, the engine says that Black is better off going for 23...Nc5 and not allowing the further attack that White has.
Very interesting and informative!
0.75 out of 1 seems fair today.
|Oct-19-13|| ||King Sacrificer: <gofer: What was wrong with <23 ... Qa4>?>|
Yeah, that move looks okay.
|Oct-19-13|| ||kramputz: <chrisowen> you talk too much|
|Oct-19-13|| ||Kikoman: <Puzzle of the Day>|
21. Rxb2! Qxb2 22. Bd4 and White is winning.
|Oct-19-13|| ||Doniez: For the first time I got the first 2 moves! This is enough for me.|
|Oct-19-13|| ||FSR: Late to the partie. I'm going with 21.Rxb2 Qxb2 22.Bd4 and now:|
22...Qb4 (eyeing d4) 23.Nh5 intending Qg3+;
22...Nc5 23.Nxf5!! Qxd4+ (23...Nxd3 24.Nh6#; 23...Rxf5 24.Qg3+ winning Black's queen) 24.Qxd4 Rxf5 25.Rf3 and Black's king isn't long for this world.
Unless I'm missing something, this seems pretty straightforward for a Saturday.
|Oct-19-13|| ||Patriot: 21.Rxb2 Qxb2 22.Bd4 Qb4 23.Nxf5 Rxf5 24.Qg3+ Kf8 25.Qg7+ Ke8 26.Bc3 Qc5+ 27.Kh1 and 28.Re1+ looks interesting.|
Another possibility is 21.Nxf5 Qxf5 22.Qxf5 Rxf5 23.Rxb2 Rxd5 but I think white is on the defensive here.