White to move and checkmate in 25 moves!! Have fun and yes, Black’s four pawns are about to Queen! 🙂
4K3/7R/8/N7/8/7B/1p1p1p1p/k1n5 w – – 0 1
Zacharov, 1976
Chess Daily News from Susan Polgar
Insane or fun puzzle?
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Insane.
This is impossible =O
this is an insane and impossible puzzle, this is a draw
STOP TRICKING US, MAKING US THINK THE PAWNS IS IN THE 7TH RANK OF WHITE!!!!!!!
GRRRRRRRRRRRRRRRRRRRRRRRRRRRRR
this is a draw, i check this with my engine 0.00!!
maybe my engine has defects,lol
Easy, but very nice (1.Nb3+ and so on). Anyway, it seems to me that it is mate in 25 moves, how it is possible in 23?
Roberto
1.Nb3+ Nxb3 2.Ra7+ Kb1
3.Bf5+ Kc1 4.Rc7+ Kd1
5.Bg4+ Ke1 6.Re7+ Kf1
7.Bh3+ Kg1 8.Rg7+ Kh1
9.Bg2+ Kg1 10.Bd5+ Kf1
11.Bc4+ Ke1 12.Re7+ Kd1
13.Bxb3+ Kc1 14.Rc7+ Kb1
15.Bc2+ Kc1 16.Bf5+ Kd1
17.Bg4+ Ke1 18.Re7+ Kf1
19.Bh3+ Kg1 20.Rg7+ Kh1
21.Bd7 wins
1. Nb3+ Nxb3 2. Ra7+ Kb1 3. Bf5+ Kc1 4. Rc7+ Kd1 5. Bg4+ Ke1 6. Re7+ Kf1 7.
Bh3+ Kg1 8. Rg7+ Kh1 9. Bg2+ Kg1 10. Bd5+ Kf1 11. Bc4+ Ke1 12. Re7+ Kd1 13.
Bxb3+ Kc1 14. Rc7+ Kb1 15. Bc2+ Kc1 16. Bf5+ Kd1 17. Bg4+ Ke1 18. Re7+ Kf1
19. Bh3+ Kg1 20. Rg7+ Kh1 21. Bd7 f1=B 22. Bc6+ Bg2 23. Rxg2 d1=Q 24. Rg8+
Qf3 25. Bxf3#
{White mates} 1-0
1.Sb3+ Sb3 2.Ta7+ and making the only moves for both sides ends in a mate in 25.
But 1.- Ka2! is critical.
I don’t see an improvement for white in
2.Sd2 b1Q 3.Sb1 Kb1 4.Bf1 h1Q 5.Rh1 Kc2
And now it is a mate in 21 (tablebase).
21+5 = 26
Yes, this puzzle is insane and possibly flawed. I also had to check with engines (Rybka 4 and Stockfish 1.9).
It seems that the first move is 1.Nb3+. The mate in 24 happens only if Black plays 1…Nxb3. If Black plays 1…Ka2, then the evaluation is very high for White.
PS Sorry for the engine analysis, but you did not say it wasn’t allowed 😉
Definitely insane. However, it is possible. The trick is to prevent the pawns from queening until the mating net has closed.
The first move must therefore, obviously, be 1. Nb3+! since it’s the only move that prevents immediate queening. Then when Black recaptures, continue the checks to prevent queening, forcing the king across the board with the rook and the bishop like so:
1. Nb3+! Nxb3
2. Ra7+ Kb1
3. Bf5+ Kc1
4. Rc7+ Kd1
5. Bg4+ Ke1
6. Re7+ Kf1
7. Bh3+ Kg1
8. Rg7+ Kh1
Then we march the king back the other way, making sure we position the bishop to be able to capture the knight with tempo.
9. Bg2+ Kg1
10. Bd5+ Kf1
11. Bc4+ Ke1
12. Re7+ Kd1
13. Bxb3+ Kc1
14. Rc7+ Kb1
15. Bc2+ Kc1 (15…Ka1 16. Ra7#)
Now we need to get the king back to h1 one, where it will be trapped on a white square allowing the bishop to deliver mate:
16. Bf5+ Kd1
17. Bg4+ Ke1
18. Re7+ Kf1
19. Bh3+ Kg1
20. Rg7+ Kh1
Now that the king is trapped on h1, we can allow queening since it’s already too late to save the game.
21. Bd7 f1=Q
22. Bc6+ Qg2 (22…Qf3 23. Bxf3#)
23. Rxg2 (23. Bxg2 Kg1 and the game is drawn as the king can now escape the first rank)
23…d1Q (23…b1Q is the same)
24. Rg3+ (24. Rg(any) works except Rg1+, which loses instantly!)
24…Qd5 25. Bxd5# or 24…Qf3 25. Bxf3#, and it’s mate in 25, just as the puzzle said.
Nb3 Nxb3 Ra7 Kb1 Bf5 Kc1 Rc7 Kd1 Bg4 Ke1 Re7 Kf1 Bh3 Kg1 Rg7 Kh1 Bg2 Kg1 Bd5 Kf1 Bc4 Ke1 Re7 Kd1 Bxb3 Kc1 Rc7 Kb1 Bc2 Kc1 Bf5 Kd1 Bg4 Ke1 Re7 Kf1 Bh3 Kg1 Rg7 Kh1 Bd7 f1Q Bc6 Qg2 Rg2 d1Q Rg3 Qf3 Bf3 mate
1.Nb3+ Nxb3 2.Ra7+ Kb1 3.Bf5+ Kc1 4.Rc7+ Kd1 5.Bg4+ Ke1 6.Re7+ Kf1 7.Bh3+ Kg1 8.Rg7+ Kh1 9.Bg2+ Kg1 10.Bd5+ Kf1 11.Bc4+ Ke1 12.Re7+ Kd1 13.Bxb3+ Kc1 14.Rc7+ Kb1 15.Bc2+ Kc1 16.Bf5+ Kd1 17.Bg4+ Ke1 18.Re7+ Kf1 19.Bh3+ Kg1 20.Rg7+ Kh1 21.Bd7 f1B 22.Bc6+ Bg2 23.Rxg2 d1Q 24.Rg7+ Qd5 25.Bxd5# 1–0
Actually, it’s not difficult considering that white has to keep checking the king whenever possible to prevent black from promoting the pawns to Queens. This is inevitable in the end, however at that point the new Queen is forced to block a check from whites bishop but is quickly taken by white as that square is also covered by white’s rook.
Sam K
it’s very easy actually, only moves for white
nice!
The mate after 1 Nb3+ Nxb3, 2 Ra7+ is lovely. The Black King is walked from one end of the board to the other, back, and to h8 again, as White picks up the Knight and f-pawn.
However, the mate after 1… Ka2 is a lot trickier, and it may not exist if Black plays optimally, although it would be close. White would win in any case.
Its really awesome puzzle :).
1 Nb3+ Nxb3
2 Ra7+ Kb1
3 Bf5+ Kc1
Give the checks to black continuously until black king goes to h1
Then give the checks back to black king so it moves to d1. Then take the black knight(at b3) out by white bishop giving check again to black king. Then start giving checks again until the black king again goes to h1 and then the game is pretty much over no matter which black pawn convert themselves to queen. Here is one variation –
1.Nb3+ Nxb3 2 Ra7+ Kb1 3.Bf5+ Kc1 4.Rc7+ Kd1 5.Bg4+ Ke1 6.Re7+ Kf1 7.Bh3+ Kg1 8.Rg7+
Kh1 9.Bg2+ Kg1 10.Bd5+ Kf1 11.Bc4+ Ke1 12.Re7+ Kd1 13.Bxb3+ Kc1 14.Rc7+ Kb1 15.Bc2+ Kc1
16.Bf5+ Kd1 17.Bg4+ Ke1 18.Re7+ Kf1 19.Bh3+ Kg1 2o.Rg7+ Kh1 21.Bd7 f1Q 22.Bc6+ Qg2
23.Rxg2 d1Q 24.Rg8+ Qf3 25.Bxf3 and its check mate
-HH
I wouldn’t normally even attempt a solution on a puzzle like this, but I think I see how it has to start, so let’s see if I can walk through this:
1. Nb3
Black has Ka2, Kb1, and Nb3:
1. …..Kb1
2. Bf5 Ka2 (what else, now?)
3. Nd2
And, now, white has the three remaining pawns covered. Black can, of course, force the win of the bishop by playing, f1(Q) followed by b1(Q), but the endgame of N+R vs N is a winning one for white. Or
1. …..Ka2
2. Nd2
With the threat of Ra7#. As far as I can tell, black must either play Ka3 (Ka1 is mate in three starting with Ra7+ followed by Nb3 and Bf5#) or clear the way to b2 by queening the pawn:
2. …..Ka3
3. Bf5 and white can round up the pawns starting with Rh2- or
2. …..b1(Q)
Here, I tried making Ra7 work, but I don’t think it does, but it doesn’t matter since Nb1 is sufficient:
3. Nb1 Kb1
4. Bf1 h1(Q) (Kc2 5.Rc2 wins easy)
5. Rh1 Kc2
6. Rh2 Nd3
7. Bd3 Kd3
8. Rf2 wins.
This leaves, at move 1, 1….Nb3:
1. …..Nb3
2. Ra7
An only move, I think:
2. …..Kb1 (Na5 will be below)
3. Bf5
An only move, see a theme here, yet:~) Continuing:
3. …..Kc1
4. Rc7 Kd1
5. Bg4 Ke1
6. Re7 Kf1
7. Bh3 Kg1
8. Rg7 Kh1
Now, here, I had to think a bit. It is tempting to withdraw the bishop and try to deliver mate with the bishop from either e4, d5, c6, or b7, but I don’t think any of these will work. For example:
9. Bf5 Nc5! (b1Q and f1Q win too)
And white has checks on the king and the pawns start queening. Or
9. Be6 d1(Q) covering d5. Or
9. Bd7 Nd4 (covering c6 and f3)
10.Bc8 b1(Q) covering b7. Or
9. Bc8 Nc5 again.
No, at move 9, white has only one playable move that I can find:
9. Bg2 Kg1
Now, here, white has the draw after Bh3 with repetition twice more. At the moment, I am not quite sure where to put the bishop, but the diagonal of a2 to g8 seems best as it is the only one that allows the eventual taking of the knight:
10.Bd5 Kf1
11.Bc4 Ke1
12.Re7 Kd1
13.Bb3
And we have finally bagged the knight! Continuing:
13. ….Kc1
14.Rc7 Kb1
And, now, we need to walk the king back to the other corner, so
15.Bc2! Kc1 (Ka1 or Ka2 16.Ra7#)
16.Bf5 Kd1
17.Bg4 Ke1
18.Re7 Kf1
19.Bh3 Kg1
20.Rg7 Kh1
And, now, we need to find the right bishop move to deliver the mate along the a8/h1 diagonal. b7 and d5 can be covered by the queening pawns on those two files, while the check from e4 can lead to
21.Bf5 f1(Q)
22.Be4 Qg2!
23.Bg2
Here 23.Rg2 loses to b1(Q) attacking the bishop at e4! Cont.:
23. ….Kg1
And the black king will escape the 1st rank prison he has been in. At move 21, only Bd7 works:
21.Bd7 f1(Q) (only move)
22.Bc6 Qg2
23.Rg2
And, unlike the line immediately proceding this variation, no pawn can queen and attack the bishop at c6 and mate in two will follow:
23. …..d1(Q)
24.Rg3 Qf3 (or Qd5 15.Bd5#)
25.Bf3#
Not so hard once you can see the theme.
Oh, earlier this day it read “mate in 23!”, and i was a bit frustrated cause i only found one in 25…
But now i’m even not convinced about this anymore – maybe anybody can help me: my idea starts with
1. Ng6+, and if black takes the knight with his own, it’s mate in 25. But what if black plays Kh7 or Kg8??!?
the moves should be Nb3+, Ka2 or Kb1 of course…
I missed Bd7!! (the 21st move in the combination)
1.Nb3+ NxN
2.Ra7+ Kb1
3.Bf5+ Kc1
4.Rc7+ Kd1
5.Bg4+ Ke1
6.Re7+ Kf1
7.Bh3+ Kg1
8.Rg7+ Kh1
9.Bg2+ Kg1
10.Be6+ Kf1
11.Bc4+ Ke1
12.Re7+ Kd1
13.BxN+ Kc1
14.Rc7+ Kb1
15.Bc2+ Kc1
16.Bf5+ Kd1
17.Bg4+ Ke1
18.Re7+ Kf1
19.Bh3+ Kg1
20.Rg7+ Kh1
21.Bd7! fQ
22.Bc6+ Qg2
23.Rxg2! dQ
24.Rg3+ Qf3
25.BxQ mate