Monday, June 04, 2012

Memento


Black to play


What happens if Black plays 1 ... Re1 here? Does 2 e6 work?



This is the End Index

4 comments:

Jonathan B said...

An anonymous correspondent writes ...

"e6 is very much playable. In fact ..."

Well yes, but the idea is that people would show their working out. Which brings us to the second (deleted) part of your comment. I fear we may be boring you this week. You might want to pop back on Friday though.

David R said...

Yes, 2 e6 wins by force, provided care is exercised in managing tempi after the forcing sequence 2...Rxe6; 3 Rxe6 fxe6

Now 4 h3! gains one tempo to force a K entry. But not 4 h4 which does the same, but rules out a later g4 to gain a further tempo.

So now 4...Kf7 (4...Kh7; 5 Kf6 wins trivially); 5 Kh6 Kf6; and now time to force a second gain of tempo because 6 Kh7 f5 gets somewhere bad somewhat quickly!

Hence 6 g4. Now 6...hxg4 doesn't alter anything. So 6...h4; 7 g5+

Now, 7...Kf5 (7...Kf7; 8 Kh7 wins this time) and I presume 8 Kg7. I say 'presume' because 8 Kh7 looks identical, but maybe isn't. I'd play 8 Kg7 instinctively, being alert to issues arising after ...e5. Haven't worked it out though. But Kh7 can't be better than Kg7, surely.

Anyhow, 8 Kg7 Kxf4; 9 Kxg6 and the g5 pawn runs faster than the e6 pawn

Jonathan B said...

Top of the class David. That's the winning line.

There's just one more thing you have to see - either calculate out or just understand that it must be so - to do with the fact that the pawns queen at the same time.

David R said...

Ah, right. Well, really not top of the class then. I thought the g-pawn Queen'd a move ahead.

So, for W to hold the win, one needs to know where to pop the WK after 9 Kxg6 e5. Presumably 10 Kh5 followed by the pawn race. And then, after queening, the BK is checked off to the e-file when Queens are traded on e1. And then, ta-daahh, W wins the h-pawn and scuttles his own quickly to h8

Important last bit that I didn't bother to pursue. 'Top of the class' must wait.