Monday, March 31, 2014

An ISE by any other name

Black to play and sacrifice the exchange (or not)
Topalov v Karjakin, Candidates’ (11) 2014

Well done Vishy. I’m not sure many people were thinking a fortnight ago that he’d come out of the Candidates’ on top of the pile. I certainly wasn’t. Aside from that, precisely how many World Champions have lost their title in a match and then fought their way back to another? Karpov, yes, but I’m pretty sure he’s the only one.

So what if all he’s done is earn himself an appointment to receive a hefty kick in the nuts from Our Magnus. It’s still an exceptional achievement all the same.

Anyhoo, back to the ISEs. This week we use the Candidates to ask: what exactly is an ISE?

I’ve never really been one for coming up with strict definitions of chess terms. It’s kind of fun to do, but it doesn’t really matter, does it? So what if I call something an ISE one week and then adopt a rather different definition of the term the next? Who cares?

Still, having established there’s no real reason to do this, let’s do it anyway.

So ... an exchange sacrifice:

giving up a rook for a minor piece in return for some kind of non-material compensation

Easy enough. Although I do remember that as a beginner I was confused as to why swapping rook for knight, say, counted when knight for pawn didn’t. They’re both two points different between what you give and what you get, after all. Let’s not muddy the water, though, and just tell my teenage self, "Well it’s different innit" and move on.

So giving up rook for knight or rook for bishop? What about this then:-

31 Rxg7+
Nunn - Short, Brussels 1986

White gives up rook for knight. So that’s an exchange sacrifice, right? Except that it’s not so much giving something up as delivering a forced mate in a few. Not much of a sacrifice, really.

Or how about this:-

White to play and sacrifice the exchange?
Lobron - Quinteros, Mastergame series 7

Get yourself those rather lovely Mastergame DVDs and you’ll see that Lobron plays 1 Rxe6+ in this position. Black has to recapture since ... Kd8, 2 Nc6+ forking king and queen, so 1 … fxe6 is forced, but now 2 f7+ is going to win back the rook with a promotion at the very least.

ISE or simply winning material?

Black to play

What of Topalov - Karkajkin, then? Black’s going to play 39 ... Bxe3, 40 Rxb7 Rxb7, 41 Rxb7 Bc5 giving up his rook to get Toppy’s bishop. I’ve seen various people calling this an exchange sacrifice, I thought of it as an ISE when I saw it played, but count the pieces.

Black has a bish plus six pawns, White with a rook and four. In fact they both ended the game this way fifteen moves later. Every beginner knows that three for the piece plus two for the pawns gives you your five for the rook. Another non-sacrifice sacrifice?

Well, it’s a bit different innit. Topalov could have munched the a6 pawn with Rb8-a8xa6 and there’s nothing obvious Black could have done to stop that. So at the very least you could say it was an exchange sacrifice offer. Doesn’t it count, though? If the material wasn’t actually taken?

Personally, I’d count them all. My ISE church is broad. They’re not all the same kind of SEs - and not equally I by any means - but they’re all ISEs just the same.

2014 ISE count: 34
TISE Index


Anonymous said...

I'd be inclined to suggest if a position has arisen where one player has a Rook and the other a Bishop or Knight, that the player with the piece has lost or sacrificed the exchange. Whether they get losing, drawing or winning chances is immaterial.

There was an incident in the Anreikin-Aronian game of the Candidates round 13 (the Tromp) where the engines thought White's best plan was to use an attack on f7 to force the win of the exchange. The problem was that it then left a position with Rook against Bishop but with all the pawns on the same side of the board. Rightly or wrongly Andreikin decided on another winning attempt.

If that ending had arisen and been drawn, would we have said that Aronian sacrificed the exchange for good drawing chances, or would we have said that Andreikin won the exchange by force but the resulting position was very drawish.


Jonathan B said...

Good question Roger. I guess it goes back to that old saying: "If I win the game it’s a sacrifice, if I lose it’s a blunder"