White threatens 44.Rb5+ Ka3 (44... Ka2 45.Kc2 with the double threat 46.Ra5# and 46.Rxb2+) 45.Kc3 Ka4 (45... Be1+ 46.Kc2 Bxg3 47.Rb3+ Ka2 48.Rxb2+ Ka1 49.Ra3 Ka2 50.Rxg3) 46.Rxb2 Bxg3 47.Kc4 Ka5 (47... Ka3 48.Rb3+) 48.f5.

The immediate 43... b1=Q just draws after 44.Rb5+ Ka2 45.Ra5+ Kb2(3) 46.Rb5+, etc.

The underpromotion 43... b1=N+ 44.Ke2 Bd4 is not convincing.

A better option is to cover the black king with 43... Be1+:

<43....?>

Target: 1:25;000
Taken: 1:08;828

Material: White up, +2 / +3

Candidates: b1=N†... b1=Q...?... oh, that... <[Be1†]>

-ML-
A very weird promotion problem. Black is down an exchange but has the typical 2nd rank pawn as compensation. Initially I thought Black shouldn't allow the skewer by playing b1=N†. Although this keeps the promoted piece it allows at most a draw with the f-pawns as weak as they are. So, I checked why b1=Q actually failed, and I thought I saw 43....b1=Q 44.Rb5† Ka2, and now 45.Rxb1 Kxb1 loses, so 45.Ra5† with perpetual. However, at first sight I thought Black could play 45....Bxa5 winning... well if I can make a bishop from f2 go to a5 I'll win more games in the near future by making illegal moves :). So, 45.Ra5† Kb3 46.Rb5†= DOES lead to perpetual.

Then the idea becomes obvious, no immediate promotion, and we have to utilize the piece to get the pawn on the final rank. In fact, it's then when it's clear this is an easy puzzle:

<43....Be1†!>

/A\
<44.Kxe1 b1=Q† > is in fact White's best try but toothless.

My first thought was Black promotes, exchanges Queen for Rook and a Bishop and two pawns should win against two lone pawns. However, I didn't work it out nearly as well as <dzechiel>.

Yet after reassessing the position I did come up with the winning deflection sacrfice 43...Be1+!, which wins one of two ways. If 44. Kxe1, then simply 44...b1(Q)+ (promoting with check) saves the new Queen from White's threatened skewer. If 44. Ke2, then 44...b1(Q) 45. Rb5+ Bb4 (with a key defensive interposition) does the trick.

After 44. Kxe1 b1(Q)+ the Queen versus Rook ending wins easy enough, because Black will be able to mop up the remaining White pawns due to the skewer and double attack threats against the unprotected Rook.

For example, after 43...Be1+! 44. Kxe1 b1=Q+, one possibility is 45. Kf2 Qc2+ 46. Ke3 Qc3+ 47. Ke2

[47. Kf2 Qd2+ 48. Kf3 (48. Kg1
Qd1+ ) 48... Qd1+ ;

47. Ke4 Qe1+ 48. Kd5 (48. Kf5 Qe6#) Qa5+ ]

*Obviously*, you play chess under a different set of rules than the rest of us. When your K is in check, you must rescue him from check before anything else, i.e., Rb5+ is illegal.

43...b1/N+ is an option but doesn't look all that decisive.

We have an interesting choice between 43 Bxg3 which may or may not win and 43 Be1+ which wins Q for R. If 44 Ke2? g1=Q 45 Rb5+ Bb4. Crafty will no doubt put up a tough fight, but I don't think White can construct a safe fortress, so the ending should be won (remove the Black Pawns and it is a fortress draw). Main variation Q v R ending 43...Be1+ Kxe1 44 b1=Q+ Kf2 45 Kf2 Kc4! 46 Rh8 (threatening Re8 barring the WK) Qb6+! 47 Kg2 Qc6+! 48 Kf2 Kd5 and Black has successfully approached the Pawns. Time to check:
=======
White resigns - very unimaginative. Crafty of course plays on:

click for larger view

43...Be1+

If 44 Kxe1, then b1=Q+ wins.

If 44 Kd3 b1=Q+ 45 Rb5 Bb4 wins

And on other king moves, 44...Kb4 wins.

Time to check.