Tuesday, May 27, 2014

Rook and Pawn endgame improvement



White to move. What's the best continuation for White?

3R4/4p1kp/1p2Pp2/p4p2/P5r1/6P1/4PP1P/6K1 w - - 0 1

16 comments:

s.k.srivastava said...

1f4 wins

Anonymous said...

f4 cuts off black rook

Consul said...

1. f4, and quick!

pht said...

To Yancey Ward:

Thanks a lot for your contribution on last weeks complicated puzzle.
I left a final comment on it, with slightly different lines, but the conclusion is that white wins like you claimed he does.

pht said...

For a microscopic moment I looked at Re8 and Rxe7 to get a free advanced pawn in e file, but it doesn't seem to work.

Quite obviously enforced seems:

1. f4! Kh6 (what else to free rook from prison?)

And now likely looked:

2. Rb8(?) Rg7
3. Rxb6 Rg8
4. Ra6 Rc8
5. Rxa5 Rc1+
6. Kg2 Rc6!

Oops! With e6 hanging white doesn't look that good as he initially looked. Certainly white has the free a pawn, but it looks drawish to me now, since white rook is in front of his pawn (behind was better). I wonder what went wrong here....

pht said...

Correcting my first line:

1. f4 Kh6??
2. Kf2!! black resigns.

Indeed, in this line as long as white rook simply stands lazily in 8th rank and does nothing, neither of black's rook nor king can break out of this cage now, so white's free running king can decide this game all alone, eating b6 etc..

But still we can improve for black and make it a good deal more complicated:

1. f4 h5!! (actually enforced and good)
2. Re8(!?) Rg6 (best move)
3. Rxe7+ Kf8
4. Rb7 Rg7!
5. Rxb6

Well, white looks better, but I'm far from sure how white wins this. Is there still an improvement to find?

Anonymous said...

No need to analyze variations -- 1. f4! cuts the Black rook out of the game. It won't get out in time to prevent White from picking up Black's Q-side pawns.

Anonymous said...

1.f4! boxes up the rook for at least 2 moves while white cleans up black queen side pawns!.
A>1..h5.2.Rb8.h4.3.Kf2.(not Kg2 for it allows 13..Rxe2+ and 14..Ra2!)hxg.4.hxg.Kh7.5.Rxb6.Rg8.6.Rb7!(confining black rook in 8th rank preventing it attacking white e pawn from 6th rank!).Rf8. 7.Ra7.Kg7.8.Rxa5. Rc8. 9.Ra7!.Kf8 (to protect e pawn and free the rook).10.a5.Rc6.11.a6.Rxe6. 12.Ra8+!.Kf7.13.a7.Ra6 White should win this position easily though there are some issues to solve. Black King cannot reach 8th rank because of the white rook, cannot leave 7th rank to move to 6th rank due to 8th rank check followed by queening. Black rook can only mar time on a file till the black king can come to b7 through Ke6,Kd7,Kc7,Kb7 in 4 moves. White king can reach b6 by that time. White can even give up his a pawn and capture black's e pawn followed by rook exchange to win easily the f pawns. Likely play would be:-
14.Ke3.Ke6.15.Kd4.Kd7.16.Kc5.Kc7. 17.Re8!.Rxa7.18.Rxe2+.Kb8.19.Rxa7.Kxa7.20.Kd6.Kb8.21.Ke6.Kc8.21.Kxf6.Kd8.22.Kxf5.Ke8.23.Kf6.Kf8.24.f5! and queens f pawn as he has the opposition!
B>1..h5.2.Rb8.Kh7.3.Rxb6.Rg8.4.Rb7! as in A above. The only difference is that both h pawns remain (a weakness for black) and the white king is on g1 instead of f2. Thus when black king reaches c7 the white king will be at d4 instead of c5 as in variation A. This is better for white as his King nearer the f pawns when the rooks are exchanged.

Harry

pht said...

Ah, how slow can my brain be really?

1. f4 h5
2. Kf2!!

Still there was no need for rook activity! Absolutely any idea of moving the white rook was wrong!

3. ... Kh7? (better move below)
4. Ke3 Rg8
5. Rxg8! Kxg8

The simple improvement here is that instead of a rook and pawn endgame, we get a clean pawn endgame, easily won for white due to the better king.

Black rook should try to sneak out the other way, though the rout is indeed long:

3. ... h4!
4. Ke3 hxg3
5. fxg3 (better than hxg3) Rg6
6. Kd4 Rh6
7. Kd5 Rxh2
8. Kc6 Rxe2
9. Kd7 Rc2 (Rd2+ Kxe7)
10. Kxe7 Rc7+
11. Rd7!

First white rook move in this line, and here I don't see how black is going to save the game.

Trying to summarize this:

"After initial move f4, white's obvious plan is to go and eat e7 pawn with his king!"

Anonymous said...

f4 seems pretty obvious (too obvious?). It puts the black rook "in jail" for a couple of moves, saves the a4 pawn and clears a way for the white king to enter the fray.

While black extracts his rook from jail, white can focus his rook on blacks queen side pawns and produce a passed pawn (a4) with the aim of queening the a4 pawn (or exchanging it for the black rook).

pht said...

For completeness:

1. f4 Rg6(!)

Planning to come out quicker with Rh6 h4 Rg6 and Rxg3. This may actually be the critical line.

2. Rb6?!

Interesting try.
For earlier mentioned reasons, Kh3 still isn't playable (rook never gets out), the plan Rh6 etc. can only work after white has decided to advance his king, as he would not do after Rh6, then Rxb6 works quite well, so there is no alternative to:

2. ... h5

But now white should have second thoughts about his king plans, since black gained a tempo related to this on white's Rb6.

3. Rxb6 Kh7 (h4 and sneaking out rook that way must be too slow now)
4. Rb8 Rg8
5. Rxg8 Kxg8
6. Kf2 Kf8

To be frank, here I don't spot the win for white now.
I miss a tempo somewhere.
I must still have missed something in this puzzle...

Anonymous said...

f4

Yancey Ward said...

1.f4 without a second of hesitation. Black will be forced to take too much time to free the rook while white's rook gobbles up the weak, backward black pawns.

PROF.S.G.BHAT said...

I do not go for any variation but play 1.f4 which would keep black R crippled. Of course it immediately protects QRP.

Anonymous said...

f4! is killer

Consul said...

I wouldn't care of the exchange of rooks: either the white king will stop the black a pawn in time, or the white b pawn will promote (with check) before it. Without the exchange of rooks, the b6 and e7 pawns will fall. A possible variation is:
1. f4 .. h5
2. K f2 .. K h7
3. R b8 .. h4 (exchanging now is a simple won pawn endgame)
4. Rxb6 .. Rg8
5. R b7 .. R e8 (R c8/d8, 6. Rxe7+)
6. R a7