Allowing black to simply win the pawn is out of the question, so the question is between Ke7 and Ke6. One takes the king further from black’s pawn and allows black to sacrifice the rook with check, while the other allows black complete freedom to protect his own pawn with his king.
1. Ke7 c3 loses for black, however he has alternatives. If black sacrifices the rook immediately, 1… Rxd7+ 2. Rxe7 Kc5 and there seems little hope for white to get his king in play. If 1. Ke6 Rxd7 2. Rxd7 Kc5 3. Ke5 however is surely won for white.
However 1. Ke6 black need not sacrifice since the black rook inhibits both white king and rook, he can play 1…. Kc5 and white is helpeless to stop a draw.
1. Ke7 Rxd7+ 2. Rxe7 Kc5 3. Kd6 Kb4 4. Kd5 does reach the pawn after all, so that should win for white.
1. Ke7 Kc5 and after Kxe8 it is white who can afford to sacrifice a rook.
Tougher than the earlier one, but similar ideas.
1. Rd6 c3
2. Rd6+ Kc7
3. Rd4 Rxd7+ (3. … c2; 4. Rc4+)
4. Rxd7+ Kc6
5. Rd3
1. … Rxd7+
2. Rxd7 Kc5
3. Ke6 c3
4. Ke5 Kc4
5. Ke4 c2
6. Rc7+ Kb3
7. Kd3 and the pawn falls.
1. … Rxd7+
2. Rxd7 Kb5
3. Rc7 Kb4
4. Kd6 Kb3
5. Kd5 c3
6. Kd4 c2
7. Kd3 and the pawn falls.
Allowing black to simply win the pawn is out of the question, so the question is between Ke7 and Ke6. One takes the king further from black’s pawn and allows black to sacrifice the rook with check, while the other allows black complete freedom to protect his own pawn with his king.
1. Ke7 c3 loses for black, however he has alternatives. If black sacrifices the rook immediately, 1… Rxd7+ 2. Rxe7 Kc5 and there seems little hope for white to get his king in play. If 1. Ke6 Rxd7 2. Rxd7 Kc5 3. Ke5 however is surely won for white.
However 1. Ke6 black need not sacrifice since the black rook inhibits both white king and rook, he can play 1…. Kc5 and white is helpeless to stop a draw.
1. Ke7 Rxd7+ 2. Rxe7 Kc5 3. Kd6 Kb4 4. Kd5 does reach the pawn after all, so that should win for white.
1. Ke7 Kc5 and after Kxe8 it is white who can afford to sacrifice a rook.
It seems to me 1. Ke7 is necessary.
Ke7 white wins
1.Ke7 c3 2.Rd3
if 2…Rxd7 3.Rxd7 c2 4.Kd8 c1=Q 5.Rc7+ 1-0
if 2…c2 3.Rc3+ kmoves 4.Kd8 1-0
After 1 Ke7 c3 only 2 Rd6+ wins.
Indeed, after 2 Rd3 Rxd7+ 3 Rxd7 Kc5 =
Therefore, today 1 Ke6 is wrong 1..Kc5=
Olimat