Move 49

[WMHalsdorf]

52 Rc7 forces Black to commit the bishop to a square that makes it easier to capture one of pawns. It would help if I could see the line that you seem to see that I don't . I'm curious as to what you would do after 52. Rh7 Kg5 53. Rf7 Kg4

[LaurV]

[QUOTE=WMHalsdorf;386669]52. Rh7 Kg5 53. Rf7 Kg4[/QUOTE]
??? Huh? that line is the worse they can do!

54 Rf4+

if (A) ...Kg5 or Kh5, then 55 Rf5+ and they lose the horse and/or the bishop (and mate in mostly 20 moves).

if (B)...Kh3, then 55 Kf2 and the only way to avoid the [U]mate in one move[/U] is to check with the horse (bishop takes the horse for free! if Nd3, or rook takes horse for free if Ne4) or check with the bishop (rook takes the bishop for free if Bd4, or, if Be1+ then Kg1 and [U]mate in one[/U] again). The "longest" in this case seems to be 55 ... Ne4+ 56 Rxe4 Be1+ 57 Rxe1 Kg4 58 h3 Kxh3 (if Kh5, Re5 mate; if Kg5, Re6 and mate in one) 59 Re4 and mate in one. So, 54 ...Kh3 is mate in 6, mostly.

Back to version (A), 55 Rf5+, if the king goes back to g4, we are in the same situation, but they have no horse. Mate in 6 or 7, they can't escape with the king. If 55...Rg6, then 56 Rxc5 check! (from bishop) and he escaped with the king, but lost both the figures, for free. As said, we won't need those 20 moves to mate them with the rook and the king, maybe [STRIKE]10 moves[/STRIKE] 15 moves would be enough, and we even don't need to transform.

Therefore, [B]52 Rh7 Ke5[/B] or [B]52 Rh7 Bb4[/B] (achieving what you wanted with Rc7, hehe, as side effect) is the only way to go for black. And we get the pawn for free, TOTALLY for free.

[WMHalsdorf]

Missed the obvious 54 Rf4+ so we are in agreement.