Problem #10

I found this puzzle on lichess.org, and failed to find the solution. White to play:

[Show solution][Hide]
1. Rg5!, preparing Rxf6 and Rh5#. The immediate 1. Rxf6 does not work in view of 1. ... gxf6 (1. ... Bxf6 2. Rf5 and White again mates).

Problem #9

The position below was reached after 22. ... e4 in a 90+30 game on lichess (full game is below). Black played e5 to defend against Rd3+. A few people were spectating the game, and one user found, several minutes later, the best move that could have been played in this position. It's such an unexpected move that at first I thought the user was kidding...

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23. h4!, an amazing move that allows White to bring the remaining rook into the attack with Rh3+, now that Rd3+ is no longer viable. This is the only move that yields a winning attack (Stockfish sees a mate in 13 instead of the +3 score for the next-best move). Stockfish suggests 23. ... Ng4 24. Rh3+ e3 25. Bxg4 and mate in 11, or 23. ... e3 Rd3+ and mate in 8 as possible continuations.

The full game is available here (White missed the best move at move 23):

Problem #8

The next position is obviously a won endgame for White: I am up a Bishop and a pawn in a R+B vs R ending. The game could go on for a while though, taking pawns and trying to queen one and all that stuff. But I have a faster way to end the game. What is it?

White to move

To see the solution, just highlight the hidden text below.

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Solution:

29. Rf8+ Rg8 30. Rxg8+! Kxg8 31. e6!! : the entombed King. Now his King can only go to either h8 or g8. I don't even have to use my King because I have a 3-2 pawn majority on the Queenside; I quickly activated my pawns, and my opponent was forced to resign 4 moves later, as it was mate in 3.

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Problem #7

The last problem was more than 2 months ago. Time for a problem!

I played this game earlier today. I have reached an obviously winning position, but I had to definitely take my time there to find the winning path. It's actually a mate in 6! (Well, technically it's mate in 7 given that White has Qxh2+ at some point, delaying the mate for one more move, but we all know in practice that he wouldn't play that move). Note that the mate in 6 is the only mate in the position, as confirmed by computer analysis.

White to move

To see the solution, just highlight the hidden text below.

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Solution:

20. Qg6 Kg8 21. Qf7+ Kh8 22. Ng6+ Kh7 23. Ne7+ Kh8 24. Qg6 1-0. White will play Qh7# either next move or after Black throws in the sorry 24. ...Qxh2+.
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Problem #6

This is taken from a game I just played today on Facebook, via the Chess application, which allows you to play correspondence chess games. Before the position arose, my opponent was up a pawn. He played 17. ...d5, and I replied with the tactic 18. Nxd5! Bxd5?! (D) (better was 18. ...exd5!, with many complications but keeping at least the advantage of a pawn).

Can you find White's best reply?

White to move

To see the solution, just highlight the hidden text below. (download PGN)

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Solution:

19. Qxc2! (only move that equalizes) Bxa2?? Much better was 19. ...Bb7, admitting that 18. ...Bxd5 was a mistake, and retreating. Black would have lost back the pawn won earlier; but instead, he walks into a forced mate!

The game continued: 20. Ba6+!! Kd7 (20. ...Kb8 21. Qc6±) 21. Bb5+! Kc8 (21. ...Kd6 21. Qc6#) 22. Qc6 Bd5 (delaying the inevitable) 23. exd5 Kb8 24. Ba6 1-0. Black resigned because he gets mated next move with 25. Qb7#.

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Problem #5

This problem is taken from Laszlo Polgar's "Chess". Most problems are rather very easy, but this one gave me a hard time...-

Mate in 3

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White to move

To see the solution, just highlight the hidden text below.

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Solution:

1. Qc4 Kxc4 2. e4, and no matter what Black does, White mates with either 3. Nd6# or 3. Na3#.
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Problem #4

This is not the kind of problems you are used to. This is more like a "positional chess problem" than a tactics problem. Even though the position is one of attack and defense, it doesn't have anything to do with it. So I warn you: don't look for mates, or forks, or stuff like that.

The game was played in 1990, and is between Kamsky and Petursson. The game started with a King's Indian Defense.

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Kamsky - Petursson, 1990

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White to move

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To see the solution, just highlight the hidden text below.

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Solution:

1. h6 Bh8 2. f5!, and the Bishop is in a prison. White effectively played "up a piece" for the rest of the game, and Black eventually resigned in an opposite-color bishop ending. Black's Bishop never left its cage.
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Problem #3

What's impressive about this problem, is that White saw an incredible combination, very hard to see. I guess he thought his position was so huge that there most likely was something forcing to do, but he definitely had to search deep to find it. And White is not even some kind of top GM -- just a "regular" grandmaster, rated 2518 (around 2510 at the time of the game).

The following position arose:

White played the incredibly strong 1. Nxc6!! Nxc6. Black didn't have much choices there: not only would he have lost a whole lot of material had he not captured, but he'd still have to deal with a very strong attack. Chessmaster XI gives White a minimum advantage of the equivalent of 6 pawns (+6.00), no matter how Black responds.

Can you see why Maksimenko sacrificed his Knight?

Maksimenko - Nielsen, 2003

White to move

To see the solution, just highlight the hidden text below.

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Solution:

2. Qxh7+! Kxh7 (2. ...Kf8 3. Qxg7+ 4. Ke7 Qxf7#) 3. Rh3+ Kg8 4. Ng6!, and Black will get mated with Rh8#.

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Problem #2

The first World Computer Chess Championship was held in 1974 in Stockholm. It was won by a computer named Kaissa, at the time rated around 1700.

At the end of the 1970s, computers reached the expert level (ELO 2000). And in 1977, in another World Computer Chess Championship -- this time in Toronto --, Kaissa found its match. It played against Duchess, and you'll have understood it by now, it is Duchess that won the game.

In the assistance were around 500 people, among which we could find computer-specialist IM Levy, and former World Champion GM Botvinnik. Rumor has it that nobody (or very few) had seen the variation that was played. But let's cut to the chase, and see what the fuss is all about.

Duchess - Kaissa, 1977, Toronto

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White to move

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To see the solution, just highlight the hidden text below.

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Solution:

1. Rxd6 Qxd6 2. Qa8+ Kg7 3. Qf8+!! Kxf8 4. Bh6+, and mate follows.
Of course, being a computer, Kaissa didn't resign nor move its king to g7; instead, it just played 2. ...Re8, and went on to lose the game, without much surprise there.
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Problem #1

This problem has kind of an obvious solution, but the future problems should not be as easy, so you might as well like it while it lasts.

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Bogey-Patou (ICC), August 2006

3-minute game

Black to move

To see the solution, just highlight the hidden text below.
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Solution:

1. ...Rxd5! 2. exd5 Qf4!! 3. dxe6 Nf1+ 0-1
Black resigns in view of 4. Kh1 Qh2+!! 5. Nxh2 Ng3#. A weird variant of what looks like a smothered mate.
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