[tortoiseNhare]

Originally Posted by binand

Please show moves beyond 27 too. After 27... Kg7 28. Ra8 I can't see any possibility of a win for black.

28. Ra8 Rd4 (threatening the queen followed by mate at d1)
29. Qb3 Qxe4+ (if 29. Qc2 then Qf6 leads to mate at g2)
30. f3 Qe2 (mate at g2 follows)

The tab played this way:
28. f4 Rd4
29. Qc2 Qf3
30. d6 Rxe4
31. Qf2 Qc3
32. Rd1 Re3
33. fxe5 Rf3
34. Qe2 Qc5+
35. Kh1 Rf2
36. Rc8 Qb6
37. Qb5 Qe3
38. Qd5 Qe2 leading to a mate.

[binand]

Originally Posted by tortoiseNhare

28. Ra8 Rd4 (threatening the queen followed by mate at d1)
29. Qb3 Qxe4+ (if 29. Qc2 then Qf6 leads to mate at g2)
30. f3 Qe2 (mate at g2 follows)

OK, that makes sense, but I thought it wouldn't amount to anything after 29. f3. Of course if white moves the queen before f3 it allows either Qe4 or Qf3 leading to disaster.

Originally Posted by tortoiseNhare

The tab played this way:
28. f4 Rd4
29. Qc2 Qf3

That 28. f4 seems to me is a blunder, allowing Qf3 by black.

[tortoiseNhare]

Originally Posted by binand

OK, that makes sense, but I thought it wouldn't amount to anything after 29. f3. Of course if white moves the queen before f3 it allows either Qe4 or Qf3 leading to disaster.

That 28. f4 seems to me is a blunder, allowing Qf3 by black.

28. f3 does lead to a win for white. Thanks for bursting my bubble!

[Dr.AD]

Originally Posted by tortoiseNhare

Playing black against my tablet I had this 'double rook sacrifice' moment. I could get a win after
25. ... Rxc4 26. Nxc4 Rxc4

Unfortunately Rxc4 does not win. It only wins if White plays terribly and falls in the trap of taking the second rook too. But with correct play, White easily wins.

In fact, this position is lost for Black and White has a winning advantage and will win even if Black plays Rxc4.

Originally Posted by binand

OK, that makes sense, but I thought it wouldn't amount to anything after 29. f3. Of course if white moves the queen before f3 it allows either Qe4 or Qf3 leading to disaster.

Correct! 29. f3 thwarts any threats from Black and White has a totally won game after 29. f3.

[binand]

Anyone following the FIDE World Cup/Women's World Cup in Sochi? I could only catch the latter half of Vaishali's game yesterday:

https://www.chessgames.com/perl/chessgame?gid=2061827

I think she was totally winning at the 36-move mark, but 37. a7 looked premature to me. She should have gotten her knight to d5 (totally locking c7 for herself) before attempting to promote her pawn for instant victory (which she could have done without loss of tempo via e7).

[binand]

Originally Posted by binand

Anyone following the FIDE World Cup/Women's World Cup in Sochi?

Was reviewing yesterday's games and came across this gem:

https://www.chessgames.com/perl/chessgame?gid=2061894

Fast forward to 16. Bh3. Assess the position for yourself. Then play through the remaining 10 moves to see how badly white got blindsided - resulting in a stunning checkmate that involved a queen sacrifice.

[Dr.AD]

Originally Posted by binand

Was reviewing yesterday's games and came across this gem:

https://www.chessgames.com/perl/chessgame?gid=2061894

Fast forward to 16. Bh3. Assess the position for yourself. Then play through the remaining 10 moves to see how badly white got blindsided - resulting in a stunning checkmate that involved a queen sacrifice.

Wow! Amazing game. Thanks a lot for sharing. There are so many interesting ideas and lines in this game.

BTW, looks like White missed an interesting tactic that could have saved the game. 19. Qxe4!

19. Qxe4 dxe4 20. Rxd7 Qf6 21. Rxb7 was a lot better than 19. a3? that White played. 19. a3 looked like a blunder.

BTW that 16. Bh3 is a funny move. Most would have probably played Bg2 there. It is always a bit risky to play g3 to fianchetto the bishop, but eventually not doing that and leaving the diagonal weak. Also the c3 knight was a major weakness especially after Black was allowed Bb4.

Fantastic game!

[Dr.AD]

This is a nice position from one old game. The position is quite famous and many of you might know this. But this came up recently in one chess group discussion, and thought of sharing here.

White to Play and Win. What is the best move?

[doxinboy]

Nf5 Rh6,
Rh6, gh6
Qc7

[Dr.AD]

Originally Posted by doxinboy

Nf5 Rh6,
Rh6, gh6
Qc7

No, that is not right. In your line, after Qc7, Black has Rxc7.

[doxinboy]

Nf5+ your move? Let's play live. It's fun if we are live

[doxinboy]

Nh6+ Bh3
Nf8+ Kh6
Nf7+ kh5
Qc5+

[binand]

Originally Posted by Dr.AD

White to Play and Win. What is the best move?

I haven't checked this, but my son (to whom I sent this) says Qe6 leads to a forced mate in 3.

[Dr.AD]

Originally Posted by doxinboy

Nh6+ Bh3
Nf8+ Kh6
Nf7+ kh5
Qc5+

No, that is a wrong line again. Since you already played Kh5 for Black, there is no check on Qc5. If you just play Qc5 anyway, Black has Qxg2#. And even if you play Qc5+ one move earlier before Nf7+, there is no forced mate. Black has escape paths in that line.

Originally Posted by binand

I haven't checked this, but my son (to whom I sent this) says Qe6 leads to a forced mate in 3.

Correct! Qe6 is the move! The brilliant move that is beautiful in so many ways!

The idea is this: Black has to key defenses. One is Bxh3 idea which thwarts White's tactics starting with discovered checks by Knight. And second, In case of Nf5+ which would block the Bishop, Black still has Rh6 as a defense. Thus the Rook on a3 and Bishop on c8 are the two key defenders. White needs one move which will block both these.

And 1. Qe6! is that magical move.

There are three lines after this, all are forced mates.

A) 1. ... Bxe6 (now the Rook is blocked, so Rh6 is no more a defense). 2. Nf5+ Kg8 3. Ne7#

B) 1. ... Rxe6 (now the Bishop is blocked, so Bxh3 is no more a defense) 2. Nhg6+ Kg8 3. Rh8#

C) 1. ... Nxe6 (Now any of the above two lines work again, as both Rook and Bishop are blocked) 2. Nhg6+ Kg8 3. Rh8#

BTW, this famous game was played back in 1853! This position is from Sam Loyd vs VS Moore, 1853!

[binand]

Found this old one as a FEN in a forgotten Google doc. I believe I got it from Susan Polgar's blog.

Simple enough - white to play and win. What she asks in her puzzles is "what is the best continuation for white?".