Wednesday, November 10, 2010

Test Your Defence

Here's a position for you to sweat over, from a variation that could easily have arisen in a recent game of mine. It's black to play . . .



. . . and defend. Yes, black is a piece for a pawn up - but white has just played 14.f4, threatening 15.e5. What would you play? And why? With what follow-up in mind? At the board I had completely the wrong idea - and my opponent and I fared little better at working out the truth of the position in the postmortem.

See if you can do better.

12 comments:

Jonathan B said...

Did you offer a draw?

Tom Chivers said...

Haha! No.

Tom Chivers said...

Btw - white is objectively worse, so a draw offer wouldn't be a Typical Chivers one.

Chris said...

My first reaction (time limited at work) is to move Nbd7 to solidify the support of the knight and take the pawn for piece hit. Haven't gone too far into the line, what are your thoughts?

Tom Chivers said...

14...Nbd7 is ok - to play it you must see that after 15.e5 dxe5 16.dxe5 Nxe5 17.Qxd8, 17... Nf3+! leads to a drawish endgame.

That variation isn't black's best however, and 14...Nbd7 wasn't the move I had planned...

PJM said...

14...Nc6 in order to hop to e7 (to break the pin) and possibly then g6 (to blockade the king) if something like 15. d5 happens.

15. e5 dxe5 16. fxe5 (16. dxe5 Qxd3) Nxe5 is the point.

Tom Chivers said...

14...Nc6 is the move I had planned, and I thought 15.d5 exd5 16.cxd5 Na5 was promising for me - although actually the computer thinks white has a convoluted way to reach an equalish endgame, which I'll leave you to work out :)

I think if after d5 the c6 knight goes to e7 white has an easy draw by taking on f6 and checking - because if ..Ng6 then f5 and white is better.

Give it enough time and the computer, btw, thinks that black's position is quite a lot worse if 14...Nc6 is met by the simple 15.Rad1. This makes sense: black can't unpin the f6 knight after 14...Nc6, so white can build up slowly, despite black's extra piece.

No-one has found black's best 14th move, no-one has find the best defensive idea in the position. It really is quite interesting - I'd welcome more attempts - like I say, I was nowhere near in the game or in the postmortem.

Anonymous said...

How about 14...cxd4 15. cxd4 b5!?

Richard

PJM said...

14...Re8 with the idea of hiding the king on e7 behind the wall of pawns? Following this, black will have the g and h files to attack down too.

Tom Chivers said...

Richard is correct! Well done.

The immediate point is 16.cxb5 Nbd7 and now 17.e5 just loses: 17...dxe5 18.dxe5 Qb6+. So the pin can be broke and black will say a piece up.

It is still pretty complicated. The computer's preferred top line leads to a position where it says black is half a pawn better.

Anonymous said...

14...cxd4 15. cxd4 b5 16. Qh3! intending Qh4 and swinging a rook behind it

Tom Chivers said...

Ah ha! A new twist. 16.Qh3 is indeed a promising move, not the least because 16...Nbd7 can then be met by 17.e5. I will give Rybka some time to look at it. Thanks!