2K5/4N3/p4P1k/P7/4r3/8/8/8 w – – 0 1
White to move and win.
NOTE: It is VERY tricky!
Benko, 1997
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2K5/4N3/p4P1k/P7/4r3/8/8/8 w – – 0 1
White to move and win.
NOTE: It is VERY tricky!
Benko, 1997
Nf5+ followed by f7. If 1. Nf5+ Kg6 2. f7 Kf7 then 3. Nd6 forks King and Rook and then white wins.
Nf5 and f7 seems winning
At first, I didn’t really see this puzzle as all that tricky, but I now see why. Let’s get the non-tricky lines disposed of first:
1. Nf5 Kg6 (alternatives below)
2. f7 Rc4 (Kf7 3.Nd6 fatal fork)
3. Kd7
I think Kd8 should win, too- white just doesn’t want to allow a check from b4 since white can no longer fork the rook and king. Continuing:
3. …..Kf7 (what else now?)
4. Nd6+-
And, at this point, all seemed fairly trick free to me. I could see that at move 1, Kg5 loses immediately to 2.f7, and, of course, Kh5 loses to Ng3 forking from that square, however, I almost overlooked the stalemate that arises if white is careless after black plays 1. …Kh7:
1. Nf5 Kh7
2. f7 Re5!
This move has two sharp points to it:
3. f8Q? Re8!!
4. Qe8 stalemates black! The other point of 2. …Re5 is that it does white no good to underpromote:
3. f8R? Ra5 is a drawn ending.
No, at move 3 white must play Ne7, white must still avoid a stalemate. From the top:
1. Nf5 Kh7
2. f7 Re5
3. Ne7 Rb5 (Kg7 4.f8Q Kf8 5.Ng6)
4. Ng6!
If white plays 4.f8Q, black plays Rb8 and stalemate arises after 5.Kxb8. If white underpromotes, black again takes the last white pawn for a more prosaic draw. With Ng6, white takes the threat of stalemate away, guards the f8 square if black tries Rf5 or Kg7 and just threatens f8Q if black should take the knight. All black really has left is the check from c5:
4. ……Rc5
5. Kb7 Ra5
6. f8Q Kg6
With a won ending, though not easy.
You say it’s very tricky, so I’m probably wrong… but 1. Nf5+ looks like a pretty straightforward win to me. I.e.,
1. Nf5+ Kg6
2. f7 Kxf7 (what else?)
3. Nd6+ any
4. Nxe4
1. Nf5+ Kh7 (1. … Kg5 2. f7) 2. f7 Rc4+ 3. Kd7 atc. If black takes pawn (Kxf7) white will play Nd6+ winning rook on e4 or c4.
1.Nf5+ ?
Nf5
Nf5
It seems surprisingly easy at least to find a good beginning:
1. Nf5+! Kg6
2. f7!
Of course f7 is taboo. Kxf7? Nd6+ forks the rook. And black can’t play Kg7. And Rf4 doesn’t help. And Re8+ isn’t possible. So how can that f pawn be stopped?
2. … Rc4+
3. Kb7 Rb4+ (Kxf7? Nd6+ was still a fork)
4. Kxa6 Kxf7
Very enforced so far. From here more thinking is needed. My first idea was the “obvious” looking:
5. Nd6+ Ke6
6. Nb5 Kd7
7. Kb6 Kc8
8. a6 Kb8
9. a7+ Ka8
But I simply find my knight pinned here, therefore Nc7# isn’t possible, and I find no progress from here.
Benko must have found an improvement…
1) Nf5+, Kh7
2) f7, Re5
3)Ne7, Rb5 [3) f8=Q leads to stalemate with Re8+]
4)Ng6! now f pawn will sure to become huge advantage [4) f8=Q leads to stalemate with Rb8+]