Radiology

In a rapid game online this morning, I planned an attack well before conditions on the board were ready. My opponent failed to defend appropriately and the attack succeeded.

After some opening moves, we reached this position with White to move. I had White.

At this point in the game, I began to have fantasies about an attack along the f-file against a pinned knight. This attack requires a knight sacrifice on f7 to capitalize on the x-ray.

11.f4! gxf4

11...Bxe5 12.fxe5 Nd7 13.Qh5+-

12.Rxf4

12.Qf3 was better--battery 12...Rf8 13.exf4

12...Be7??

12...Rf8= anticipates White's threats and prevents them.

White to move

Now is the time!

13.Qe2

But. I thought that more preparation was necessary, planning to first double rooks on the f-file.

13.Nxf7!! Kxf7 14.Qh5+ Kg8 15.Qg6+ Kf8 16.Raf1+-

13...Bd7

13...Rf8 was still possible, neutralizing White's plans. 14.Raf1

14.Raf1

14.Nxf7 is less effective now 14...Kxf7 15.Qh5+ Kf8 16.Raf1 Be8 the point of Bd7.

14...Rg8

White to move

15.Nxf7! Kxf7

15...Qb6 16.Rxf6 Bxf6 17.Rxf6 Qxb2 18.Na4 Qb4 19.Nc5 is also winning for White.

16.Qh5+ Kf8 17.Qxh6+ Kf7

White to move

18.Be2?!

Throws away most of the advantage.
I considered 18.Bh7 Rg7 19.Qh5+ Kf8 but did not see the ideas clearly enough.

18...Rg6??

Black moves into forced checkmate.

18...Rg7 19.Bd3 (19.Qh5+ Kg8=) 19...Qh8 (19...Qg8 20.Rxf6+ Bxf6 21.Qxf6+ Ke8 22.Rf2) 20.Rxf6+ Bxf6 21.Qxf6+ Kg8 22.Ne2+-.

19.Qh7+ Rg7

19...Kf8 holds out longer 20.Qxg6 Be8 21.Qh6+ Kg8 22.Qg5+ Kf8 23.Rh4

White to move

White has a mate in five, which I saw to the end.

20.Bh5+ Kf8 21.Qh8+ Rg8 22.Rxf6+ Bxf6 23.Rxf6+ Ke7

23...Qxf6 24.Qxf6#

24.Rf7+ Kd6 25.Qe5# 1-0

Vulnerable King

An entertaining game from P. H. Clarke, 100 Soviet Chess Miniatures (1963) offers a lesson in vulnerability. White’s king appears more exposed, but Black’s king is in mortal danger on its starting square.

Black to move

The game is Barshauskas — Chesnauskas, Championship of Lithuania 1955. Black’s problems stem from the greater mobility and coordination of White’s forces. As Clarke notes, “It is worth remarking that while the position of the Black king in the centre is of the utmost import, the comparatively exposed state (i.e. to the normal castled position) of the White monarch is of lesser significance. The reason lies, of course, in White’s lead in development” (31).

The game continued 17…Bc5

Clarke notes that 17…Be7 would at least “admit the danger”.

18.Nxe6?

18.Bxe6 Bxe6 19.Nxe6 maintains the advantage.

18…Bxe6 19.Bxe6

Black to move

What would you play as Black? After making the wrong choice, Black resigned four moves later.

X-Ray

How difficult?

Yesterday morning, I had this position in a blitz game. While looking for tactics exercises for my beginning students after showing them Paul Morphy's Opera Game, I put this position on the demo board. We did not discuss it, as they were busy playing chess and I was working with them on basic manners and sportsmanship.

After club, I put the position on Facebook thinking most followers there would solve it quickly. Although the second person to post offered the strongest move, which I had played in the game, I was surprised at some of the other responses. Is this position more difficult than I thought?

White to move

It seemed to me that it should be easy to remove both knights and then snatch the bishop.

15.e4

The strongest move, according to Stockfish.

I expected 15...Nb4 16.Bxf6 gxf6 17.Qxd7 and a clear advantage for White, probably decisive.

Black could have made things interesting with 15...h6, when the strange looking 16.Bh4 is the engine's choice. The computer likes 16...g5 17.Qd2

Black to move

Analysis position

I would have been stunned by 15...h6, realizing that my advantage was not to be gained as easily as initially anticipated, and played 16.Bxf6 Nxf6 17.e5 Nd5 and then would have considered 18.Bxd5.

Looking through this game this morning, I found that I used a mere two seconds on the position in the first diagram. My recollection of the game was that I had used more time than that. It turns out that I had spent twelve seconds on this position the previous move. I planned 15.e4 before exchanging my knight for my opponent's bishop.

White to move

14.Nxb6 Qxb6

Now, the position is the first diagram is reached. My opponent had played 13...Bd7, placing the bishop on a vulnerable square. Superficially, this error is a simple developing move that prepares to bring the bishop to a better square while connecting the rooks.

After my 15.e4, my opponent thought for thirteen seconds. As it was a three minute blitz game, that's a relatively long think.

15...Bc6

This move surprised me, but my reply was simple and easy.

16.exd5 Nxd5

White to move

17.Qg4

Again, I played the strongest move with fantasies of getting an easy checkmate or otherwise exploiting a pin along the g-file. Nonetheless, I spent fifteen seconds on this move.

17...f6 18.Bxd5

How did I miss 18.Qxe6+? Checkmate fantasies.

We played another fifteen moves before my opponent resigned.

Slaying Blind Pigs

My low rated opponent opponent threatened a draw by repetition with his blind pigs. I was happy to find the antidote in this blitz game.

White to move

Lesson of the Week

Working with Pins

Lessons the past couple of weeks have featured positions where a pin may be exploited to gain material. Sometimes another tactic is needed to create a pin and win material.

This position occurred in an online game one year ago. Black found the correct tactic here, but later lost his way and threw away his queen. White then demonstrated that he had difficulty finding an easy checkmate.

Black to move

Bonus problems: find White's quickest rout to checkmate.

White to move

Here White missed a checkmate in one.

White to move

X-Ray

White to move