Another study by Nicolai Ryabinin. The first move isn't all that difficult to find, but finishing off the win takes some thought.
8/2p5/3P4/kr6/2p5/7K/8/3R4 w - - 0 1
OK, Yancey. I considered this line but I thought it wasn't the strongest line.
4.Rxd8 c35.Rc8 Kb66.Rf8 Kc57.Rf2 Kd48.Kf1 Kd39.Ke1 c210.Rf3+ Kd411.Kd2 c1=any piece12.Kxc1It's a winning position for white.
Yes, the line starting 1. d7 I looked at as well. Oddly enough, although it is much slower, I think that 1. xc7 wins as well:
Well, I was wrong.
According to Nalimov database, Black can draw butonly if after
Every other move there by Black loses.
Alena, good. Now you can see why it had to be 6.Rf8, but not the similar looking 6.Re8, 6.Rg8, and Rh8, right?
Illyrialady, according to my notes on this study, I pretty much settled on 1.d7 for no other reason than it was counterintuitive to 1.dxc7 which, as you note, only draws. For the me the hardest part of this puzzle was the second move and the sixth move. In some sense, I realized pretty quickly why 2.Kg2 was better than the alternatives- white must keep the king closer to c1 to stop the pawn once the rook has been won, but it took me a while to work out why 6.Rf8 was required in the second variation Alena gives above.
Yes, I understand why Rf8 is the only move to win.
a) 1...Rb8 (forced), 2. Ra1+! Kb6, 3. Rb1+ Ka7, 4. Rxb8 Kxb8, 5. d8=Q+ Kb7, 6. Qd4 and White wins
b) 1...Rh5+!, 2. Kg2! Rh8, 3. d8=Q Rxd8, 4. Rxd8 c3, 5. Rc8 Kb6, 6. Rf8! c2, 7. Rf1 Kb5, 8. Rc1 Kb4, 9. Rxc2 c5, 10. Kf3! c4, 11. Ke2 Kb3, 12. Kd2 and White wins!!!