Enlightened by Houdini

It's always educational to analyze one's games, even "stupid" games like online blitz games, with a strong engine like Houdini. In the following game, for example, I made a major tactical hiccup on move 10, which should have dropped a piece - to which I, and apparently also my opponent, were oblivious. Then I did something right, exploiting his inaccuracy on move 15, and got "an easily won game." I blundered on move 23 with a "loose" move, which he exploited with a tactic that should have left me scrambling for a draw. But just two moves later he fell into a back-rank trap that left me in an ending an exchange up. Thanks to the wonders of premove, I was able to convert it into a win despite the dearth of time on my clock.

A great teaching position

White to play and win: Rovner-Kamyschev, 1947

The Perils of Pauline (Chess Homeschool, Day 1)

Good morning, class!

The silent films heroine Pauline was always in a life-threatening predicament, but somehow always managed to escape.  Even the corny movies of the 1940s found Pauline's perils a little bit too unbelievable:

Experienced players may find the following ten positions a little corny, too.  But if they help beginners and intermediate players learn new mating patters, that's OK.

You have the White pieces and it's your move. Black is threatening checkmate in one move, so you'd better find a way to escape! Some have suggested that the best defense is a good offense.

1) White to play and win

2) White to play and win

3) White to play and win

4) White to play and win

5) White to play and win

6) White to play and win

7) White to play and win

8) White to play and win

9) White to play and win

10) White to play and win

If you're stumped, remember that Black is threatening mate. You must look at all forcing moves (moves that Black has to answer), no matter how silly they seem!

Too easy? Go for extra credit.

Too hard? If you're having trouble, ask questions in the comments.

Back rank mate practice

Nakamura-Shulman, 2010 U.S. Championship

Sunday, May 23, 2010

Black to play and win

Do these easy mating patterns have any practical application in grandmaster play?  Well, it helps to be able to spot the pattern many moves in advance.

Here's a somewhat more difficult version of the same problem.

Nakamura-Shulman, 2010 U.S. Championship

Sunday, May 23, 2010

Black to play and win efficiently

1...Nc6 does win for Black (why?), but it's not the fastest method. 

More back rank practice #8

One final pitch for the Estate of Fred Reinfeld.  This is a fun training book!

White to play and win

The pin must...not lose?

More back rank practice #7

I modified this one a little bit, as there were a zillion ways to win in Reinfeld's original position.

White to play and win

More back rank practice #6

Simple yet pleasing!

White to play and win

More back rank practice #5

Simple and pleasing:

White to play and win

One of the Amazon reviewers suggested that 1001 Brilliant Ways to Checkmate should be read after How to Beat Your Dad at Chess. That seems like good advice to me, as the latter book is much more organized. But you should really read both!

More back rank practice #4

Here's another exercise from 1001 Brilliant Ways to Checkmate, considerably more complicated that the last few we saw (but still not that hard):

 White to play and win

Can you combine pressure on h7 with the idea of mating on d8?  Don't forget that White has a bishop on b1!

More back rank practice #3

Are we clear on the concept?  And buy this book. 

White to play and win

Back to the Back Rank II: Reshevsky-Fischer continued

Back to yesterday's question. 

Reshevsky-Fischer, Palma de Majorca Interzonal, 1970

Black to move

In this position, you may have been tempted to play 28...Qe2??  It does threaten a back-rank mate in one move: 29...Qxf1#.  But White gets to go first: 29.Qxf7+! Kh8 leads to this position:

Analysis after 28...Qe2??: White to play and win

So what's the winning move?

28...Qe1?? is bad for a slightly different reason: do you see why?

Analysis after 28...Qe1??: White to play and win

Of course, Fischer was not naïve in matters on the chessboard.  He found the best move: 28...Qf4!

White to play in the actual game:
a critical position!

Switch sides for a minute and try to help Reshevsky save this position with White (hint: a grandmaster playing White would have real drawing chances against Fischer): what would you recommend?  The most important challenge is to avoid getting mated on the back rank!

More back rank practice #2

As in the previous example, the enemy king doesn't have to be castled for a back rank mate to occur.

White to play and win

More back rank practice

I hope the heirs of Fred Reinfeld will forgive me for quoting from 1001 Brilliant Ways to Checkmate

White to play and win

Back to the Back Rank: Reshevsky-Fischer, Palma 1970

Reshevsky-Fischer, Palma de Majorca Interzonal, 1970

Black to move

This is a position hard enough that eight-time U.S. Champion Sammy Reshevsky blundered horribly, but easy enough that a beginner can understand.  But take it one step at a time, slowly, and double-check you calculations!

Bobby Fischer is Black, and it's his move.  The position is probably only slightly better for Black, but Fischer would really like to win this qualifier so he can eventually play Boris Spassky.  He needs your help!

How many different ways can Black threaten back-rank mate?  Fischer did choose one such move: which one would you recommend?  Do you see any problem with any of the other possible mate threats?

Answers (and more questions) tomorrow evening....

Adams-Torre, part 7

23.Qxb7!! is the killer. (23.Qxa5 and 23.Qb6 also eventually win, but only if White finds this idea.)

After 23.Qxb7!! 

Black to play: the queen can't escape

Here's the complete game.

Adams-Torre, part 6

Carlos Torre Repetto, 1925

When Adams and Torre played this game in 1920 (or, more likely, when Torre created the conclusion of this casual game from post-mortem analysis with Adams), Torre (born in 1904) was only about 16 years old!

Let's look at moves that don't work.  22.b3 is a very logical try:

After 22.b3?: Black to move

White makes a threat that must be answered, and 22...Qxb3?? loses for the usual reason.  But Black can simply reply 22...Qb5!, and I don't see a way to drive the Black queen off the a4-e8 diagonal.  For example, 23.Qc4 Qd7! 24.Qg4 Qb5! rewinds the tape of the game, except that White has lost the a-pawn.

22.Qa5?! is a better idea, and it gives White real winning chances:

After 22.Qxa5?!: Black to move

Black's only reply is 22...Qd7, and White can press Black with 23.Qc7! Qb5 24.Rxe8+ (24.Qxb7?? loses for the usual reason: do you see why?) 24...Rxe8 25.Rxe8+ Qxe8 26.Qxb7, with excellent winning chances in the endgame.  (The helpful knight on f3 guards the e1 square, so Black has no back rank mate.)  But White has better....

After 22.Re4!!: Black to move

 

22...Qxe4 loses to a version of a trick we saw in the Bernstein-Capablanca game.  23.Rxe4! and Black can't take both unprotected pieces at once.  So Black must return the queen to b5:

After 22...Qb5: White to play and win

There are a couple moves that win, but there is only one winning idea!

Adams-Torre, part 5 continued (so what's the right move?)

Let's take another look at the position after 20...Qb5:

 White to move and win (it will take a few moves!)

We just saw that 21.Qxb7?? loses to 21...Qe2!

Another idea is 21.Qc4, but that just leads to a repetition of position after 21...Qd7:  White could then play 22.Qc7 and Black would reply 22...Qb5: back where we started.

22.Rxe8? would be OK if we didn't have something better:  22...Rxe8 23.Rxe8+ Qxe8 24.Qxb7 wins a pawn, but Black has time to make Luft with 24...g6.  The Black queen will soon counterattack, and Black has good drawing chances.

The key to this position is to realize that the Black queen is running out of squares on the a4-e8 diagonal from which it can protect e8.  The White queen controls d7; the pawn on d5 attacks the c6 square.  So if we can find some way to attack the other two squares we can win immediately.  For example:

FANTASY POSITION (imagine White's b2 pawn was on b3)

White to play: 1.a4 wins immediately!

In this example, the Black queen has no safe square from which to guard the rook on e8.

But in our game, White has no time to play 21.b3, because Black will simply make Luft with a move like 21...g6, and there is no more back rank mate threat.  If Black has time to breathe, Black will create room to breathe.

The correct move is 21.a4!  Black's reply is forced, 21...Qxa4

White to play: how to drive the Black queen off the diagonal?

And now what?  Here are four possibilities:

a) 22.b3
b) 22.Re4
c) 22.Qxa5
d) 22.Qc4

Adams-Torre, part 5 (watch your own back rank!)

After 21.Qxb7??: Black to play and win!

In the Adams-Torre game, we've seen White sacrifice his queen on three consecutive moves.  So wouldn't it be cool to sac a fourth time?  Again, if Black were to accept the sacrifice with 21...Qxb7??, then 22.Rxe8+! would lead to a back rank mate.

The problem is that Black can reply with an even cooler counter-sacrifice: 21...Qxe2!  (It's an easy move to miss: one of the commenters fell into a different version of the same trap.)

After 21...Qxe2!  White to play

Black has a forced win here, but White can try to set a trap.

If White now plays 22.Qxc8, what's is Black's winning reply?

Or if White instead plays 22.Rxe2 Rc1+ 23.Ne1 (see diagram below), how does Black force the win?

After 21.Qxb7?? Qxe2! 22.Rxe2 Rc1+ 23.Ne1: 

find the win for Black

Adams - Torre, part 4

Adams played the incredibly beautiful 20.Qc7!!

  Black to move

As in the previous position, both the Qd7 and the Rc8 are committed to protecting the Re8: taking the "free" queen leads to a back-rank mate by force.

Torre played 20...Qb5.

White to play and win (still a few moves to go!)

I'll suggest a few moves: which do you think is strongest?  Please back up your opinion with careful calculation of all the possibilities!

a) 21.a4
b) 21.Qxb7
c) 21.Qc4
d) 21.Rxe8+

Adams - Torre, part 3

Adams played the amazing 19.Qc4!!

 Wow!  Black to play

While the white queen can be taken either by the Qb5 or the Rc8, both are fatal, as Black would then have only defender of the e8 rook, and 20.Rxe8+ would lead to mate on the next move.  19.Qc4 also prevents Black tricks based on the weakness of White's back rank.  For example, 19.b3?? Qxe2! would have been a killer: do you see why?

So Carlos Torre played the only move that controls the e8 square: 19...Qd7.

White to play

What was White's reply?  How deeply can you analyze the continuations?