<51....?>

Target: 1:25;000
Taken: 1:05;593

Material: unbalanced, White / +2

Candidates: d2, Re5..... oh, <[d2]>

-ML-
A typical endgame problem, where Black has definite compensation for the exchange; two pawns of which one is passed, and the Bishop is stronger than probably either Rook. Due to the terrible White coördination, Black should have a way to gain something from the position. Initially I neglected the pawn push d2 because of 52.Rxd2 and nothing next. However, 51....Re5† or any other move results in a foggy situation where it is unclear if White can breakthrough and Black can defend, or in the other way, if Black can create a fatal breakthrough; a draw is the most probable result. So, Black HAS a clear move in this position. Than, it has to be:

<51....d2> White doesn't have any clear countermeasures against this other than capturing the pawn: the c-Rook can't return, and of course 52.Rf1 d1=Q is rather insufficient.

<52.Rxd2> so what is the key here then? Ah, of course.

<52....f4†> you don't get take-out-the-defender moves more easily than this.

<53.Kxf4> any other move loses the Rook just as much.

A) 52.Rxd2 f4+ followed by 53... Rxd2 and 54... Ra2 winning the pawn on a5 and the game.

51 ... d2

White must stop the pawn or it will promote

52 Ke2 d1=Q+ winning
52 Rf1 d1=Q 53 Rxd1 Rxd1 winning

Main Line

52 Rxd2 f4+
53 Kxf4 Rxd2 winning

White is now a bishop down and cannot defend both Pg2 and Pa5. Also Pa5 is indefensible, so white will defend Pg2 and lose Pa5 at which point white is now down a passed pawn. So in the end I am not sure when white will resign, it might be immediately after 51 ... d2, but it might be after 52 Rxd2 f4+...

for me today a little confirmation of the often mentioned rule with those small little tactics: change the move order

my first thought was 51...f4+ followed by 52...d2, but of course 52.Kd2 is an adequate defence. a little change does the trick, never forget to try...

another amazing small detail how the human brain works: many people here, me too, saw the importance of the black bishop in covering d3/e2. but d3 is irrelevant as its covered by the black rook, the only thing that matters is e2, funny

<agb2002> I'm curious why you calculated the second line, <B) 52.Rxf5 d1=Q 53.Rff7 Qe2+ 54.Kf4 Qf2+ 55.Rd4+ and mate soon.>, since even 52...Rxf5 is winning and doesn't offer a challenge to black's pawn push. No offense intended, just wondering...

I thought the right sequence is 51... f4+ and afterwards 52... d2.

I overlooked 51... f4+ 52. Kd2!

You're right. The main reason is that I felt curious about White's counter chances along the seventh rank.

I often like to explore crazy/fantasy lines (see for example B Garfinkel vs F Wren, 1933) for fun and to exercise chess calculation and lateral thinking (there's no clock ticking!).

<No offense intended, just wondering...>

I totally understand the desire, to free the rook from the burden to block that pawn and leave this duty to the king.

so instead of 49.Rc1 the immediate 49.Rf2 looks a bit more accurate to me. Now black doesn't have that nasty check on f4.

The pattern in question is the one where a king is defending a piece, but it can only defend it from one diagonal square because the adjacent squares are taken away (typically by a bishop, as in this case, or by the king's own pawns). Its a highly vulnerable defense because it's fun and easy to kick such a king.

click for larger view

In this position, I played 51... d1+ 52. xd1 b3+ 53. xb3 xd1 and my opponent resigned the game.

That's the same tactic at work here: