Pawn vs. Rook Endgame

White to play and win...

Originally posted by Spacetime
White to play and win...

[fen]8/2P5/8/8/3r4/8/2K5/k7 w - - 0 6[/fen]

Anything?

1.c8(Q) with an eye to mate the king on the edge.

1...Rd2+ 2.Kxd2 and K+Q v K
1...Rc4+ 2.Qxc4 and the same
1...Ka2 2.Qa8(or a6)+ Ra4 3.Qxa4#

1...Ra4 in order to block mate is met with 2.Qc3+ Ka2 3.Qb2#

c8 = R if C8 = Q then Rc4+ Qxc4 Stalemate

Originally posted by geepamoogle
c8(Q) with an eye to mate the king on the edge. The black rook is unable to give any meaningful check without giving itself up.

1.c8Q+?? Rc4+! and Black draws.

1.c8R! Ra4 (forced) 2.Kb3 wins the Rook or mates.

Originally posted by cmsMaster
Anything?

Oops, I should have said white to play and mate in 7...

Originally posted by Spacetime
White to play and win...

[fen]8/2P5/8/8/3r4/8/2K5/k7 w - - 0 6[/fen]

The more difficult and probably more likely endgame would be pawn vs. queen as such:



Black to move and win...

Originally posted by BigDoggProblem
1.c8Q+?? Rc4+! and Black draws.

1.c8R! Ra4 (forced) 2.Kb3 wins the Rook or mates.

Yes, that's the right answer. I thought this was pretty interesting.

No, c8=Q Rc4+ Qxc4 is stalemate. To venture a guess c8=R though i think Kc3 (Kb3?) should win also.

Actually c8=R has to be the win. After Ra4 what else does Black have?

Bleh, stinking stalemates..

Originally posted by wittywonka
The more difficult and probably more likely endgame would be pawn vs. queen as such:

[fen]8/3KP3/8/8/8/8/8/qk6[/fen]

Black to move and win...

That one is interesting too, maybe more difficult if you don't know the pattern. The one I posted is just kind of strange since it so easy to miss that c8Q draws.

Originally posted by Spacetime
That one is interesting too, maybe more difficult if you don't know the pattern. The one I posted is just kind of strange since it so easy to miss that c8Q draws.

Everyone should learn these basic techniques. And be able to explain that when you shift the pawn (and the white king legally protecting it) to the right or left, it is a draw with the pawn on a7, c7, f7 and h7 and won for black on the other squares.

Also note that there is no single winning move for black to start with here. Any of the three checks (Qa7, Qa4, Qd4) as well a queen move pinning the pawn (Qg7) is equally good.

For the following position, play should go as following (for those who don't know):



1. ... Qd4+
2. Ke8 Kc2

Black should try to move the king towards the pawn every chance he gets (i.e. whenever white can't promote)

3. Kf7 Qd7 (pinning the pawn)
4. Kf8 Qf5+
5. Ke8 Kd3 (again, advancing)
6. Kd8 Qd5+

White may try:

7. Kc8 Qe6+
8. Kd8 Qd6+

But this leads back to:

9. Ke8 Ke4
10. Kf8? Ke5 (the pawn is still pinned)
11. Kf7 Qf6+
12. Ke8 Ke6 (the pawn still can't promote)
13. Kd8 Qxe7+ (finally)
14. Kc8 Qa7
15. Kd8 Qd7#

Originally posted by Spacetime
Yes, that's the right answer. I thought this was pretty interesting.

It's the end of a famous puzzle. The beginning (I think) is this:


White wins

1.c7 Rd6+ 2.Kb5! Not 2.Kc5?? Rc1! and the new Queen gets skewered. Same goes for 2.Kb7?? Rd7 and ...RxP. 2...Rd5+ 3.Kb4 Rd4+ 4.Kb3 Rd3+ 5.Kc2! No more skewer. 5...Rd4! And now our familiar stalemate trap. 6.c8R!! Ra4 7.Kb3 and wins.