# Proof Game in 24.5

BigDoggProblem
Posers and Puzzles 29 Apr '05 21:48
1. BigDoggProblem
29 Apr '05 21:48

Position after White's 25th move. How did the game go?
2. 30 Apr '05 08:16
Three black knights !? This is bound to be interesting ðŸ™‚
3. 30 Apr '05 09:501 edit
to start off, white's 25th move is 25. b3# .
4. 30 Apr '05 10:261 edit
Black has all his pieces + one promoted knight, and lost one pawn. To make it in 24 moves, I see following options:

- the a-pawn went to d1, capturing a pawn, a knight and the queen and promoting to knight, which then went via e3 to capture the bishop on f1. Not sure if the pawn went a5 - xb4 - xc3 - c2 - xd1 or a5 - xb4 - b3 xc2 - xd1 or a5 - a4 - xb3 - xc2 - xd1

- the white knight took the h7-pawn and by leaving made the route open for the rook to go via h5 to a5, and was later captured on f6 by the g7-pawn

- the knight from b8 went via d7 to f6 to e8

- the bishop from c8 went via f5 to capture the rook on b1, the other bishop went straight to b4

- king and remaining pawns made their fastest way to the end position

This takes exactly 24 moves for black. However, I am stuck with the order in which to make the moves, since the pawns on 5th rank would block the rook move, the pawn on d6, necessary for the knight moves, blocks the bishop route, etc...

Maybe I missed ooptions, or is there a possible sequence?
5. 30 Apr '05 15:102 edits
Originally posted by schakuhr
to start off, white's 25th move is 25. b3# .
sorry no post here
6. 01 May '05 09:171 edit
So here we go with the strange travel of the white king:
1.Nf3! a5 2.Nd4 a4 3.Nb3 axb3 4.Nc3 bxc2 5.Ne4 cxdN 6.Ng5 Ne3 7.Nxh7 Nxf1 8.Ng5 Rh5 9.Nh7! Rha5 10.Kd1 e5 11.Kc2 Bb4 12.Kd3 d6 13.Ke4 Nd7 14.Kf5 Ndf6+ 15.Kg5! Kd7 16.Rb1 Ne8 17.Kg4! Kc6+ 18.Kf3 Kb5 19.Ke4 Ka4 20.Kd3 b5 21.Kc2 Bf5+ 22.Kd1 Bxb1 23.Ke1 f5 24.Nf6 gxf6 25.b3#
The difficult part is to lose a tempo for white which can only be achieved by the White king's pseudo-triangular maneuver... A nice puzzle ðŸ™‚
Edited: several typos
7. 01 May '05 10:58
Originally posted by ilywrin
So here we go with the strange travel of the white king:
1.Nf3! a5 2.Nd4 a4 3.Nb3 axb3 4.Nc3 bxc2 5.Ne4 cxdN 6.Ng5 Ne3 7.Nxh7 Nxf1 8.Ng5 Rh5 9.Nh7! Rha5 10.Kd1 e5 11.Kc2 Bb4 12.Kd3 d6 13.Ke4 Nd7 14.Kf5 Ndf6+ 15.Kg5! Kd7 16.Rb1 Ne8 17.Kg4! Kc6+ 18.Kf3 Kb5 19.Ke4 Ka4 20.Kd3 b5 21.Kc2 Bf5+ 22.Kd1 Bxb1 23.Ke1 f5 24.Nf6 gxf6 25.b3#
The difficult part is to ...[text shortened]... ieved by the White king's pseudo-triangular maneuver... A nice puzzle ðŸ™‚
Edited: several typos
nice work!

My initial attempts failed because I used the wrong knights to go for h7 resp. be captured by the a-pawn.

I understand the tempo issue, and the fact that only the king could do it, but isn't it enough to go to e4 and then make the triangle via e3 and back to d3? All remaining even number of waiste moves can be made by the rook (Rg1-Rh1). Or what am I missing?
8. BigDoggProblem