Can You Figure Out How White Wins This

This is a tough brain teaser. Can you figure out how the white knight outmaneuvers the bishop?

8/8/4p3/4P2b/7N/8/5KPp/7k w - - 0 1

Comments (15)
No. 1-15
Yancey_Ward
Yancey_Ward

Editor

1.g3 Bf3
2.Ng6 Bh5
3.Nf4 Bg4
4.Nd3 Bf5
5.Nb4 Bg4
6.Na2 Bf5
7.g4 Bxg4
8.Nc1 and black is in zugzwang because he can no longer protect the g3 square appropriately, and must give up the h-pawn and the bishop for the knight.

Yancey_Ward
Yancey_Ward

Editor

Alena, a bit more convoluted than it needed to be, but you have the right elemental position between moves 10 and and 12. Of course, Dave had found the key element in his comment derived from one of your previous lines. The most concise route is the following:

Alena
Alena

1.g3! Bf3
2.Ng6 Bh5
3.Nf8 Bg4
4.Nd7 Bf5
5.Nf6 Bg4
6.Ne4 Bf5
7.Nd2 Bg4
8.Nb1 Bf5
9.Nc3 Bg4
10.Na2 Be2
11.g4 Bxg4
12.Nc1 Be2
13.Nb3 Bf3
14.Nc5 Bd5
15.Nd3 Bf3
16.Kxf3 Kg1
17.Nf2 Kf1
18.Nh1!
It's a winning position for white.

Yancey_Ward
Yancey_Ward

Editor

1.g4? Bg4!
2.Ng6 Bf5
3.Nf8 Bh3!
4.Nd7 Bg4!
5.Nc5 Bf5!

Now think about this problem at this stage- white wants to bring the knight to g3 via e4, e2, f1, or h5. Black defends this by covering those squares with the bishop the move before the knight reaches them by staying on the h3/f5 diagonal. You will find that after move 5 (the previous moves in the line) that white can never accomplish this- the bishop has three safe squares on that diagonal, and always two safe moves while on it- that is too much flexibility for the knight to overcome to reach e2, e4, or f1. In addition, the knight can only reach h5 by coming from g3, which is irrelevant, and f6 and g7- but this also fails because black can always put the bishop on f3 safely since white can't let the black king off of h1 when the knight is on f6 or g7. This is why 1.g4 is an error- and that 1.g3 was the right start.

What you need to try to think of is a position where white can let the black king off of the h1 square safely- that is the type of position you are trying to create. What I notice about your problem solving is that you seem to always try a linear approach to them- you start of move 1 and try to work out where to go at each stage. This is perfectly fine a lot of the time, but you should always try to think about what a winning position might be- literally create one out of this problem, for example, then try to work towards that position from move 1.

Yancey_Ward
Yancey_Ward

Editor

Ok, I am going to show you a line that demonstrates the problem white has to overcome:

Alena
Alena

That's how I reached this position yesterday.

1.g3! Bf3
2.Ng6 Bh5
3.Nf8 Bg4
4.Nd7 Bf5
5.Nc5 Bg4
6.Nb3 Bd1
7.Nd2 Bg4
8.Nf1 Bh3
9.Ne3 Bg4

Yancey_Ward
Yancey_Ward

Editor

And looking at Dave's line, it seems reasonable that 1.Nf1 gets to the right place, too, but in more moves than I had in mind.

Yancey_Ward
Yancey_Ward

Editor

I think it can still be won after 8/8/4p3/4P3/6b1/4N1P1/5K1p/7k w, but I have to think about it- I think the continuation would be Nc2 in, but I can't rule out other pathways converging to the winning line. From Nc2, I can, I think see the winning path again. What sequence of moves do you use to get to the position you described?

Yancey_Ward
Yancey_Ward

Editor

If there is a mate in 16 after 2.....Bg4, then you found a line I never found, but the most tenacious defense is 2......Bh5.

DaveCubby
DaveCubby

Alena, 1. Nf1 Bh3 2. Nd2 Bg4 3. Nb1 Bf5 4. Nc3 Bg4 5. Na2 Bd1 6. g4 Bxg4 7. Nc1 Be2 8. Nb3 Bf3 9. Nc5 Bd5 10. Nd3 Bf3 11. Kxf3!! Kg1 12. Nf2! and White can stop Black h-pawn from queening.

Alena
Alena

I reached this position which I can't win with my idea 8/8/4p3/4P3/6b1/4N1P1/5K1p/7k w - -.

Alena
Alena

Do you mean 2...Bh5?

Alena
Alena

Yancey, I tried to play the position with 2...Bg4 and I got mate in16 with the same idea. Can you be more specific?

Yancey_Ward
Yancey_Ward

Editor

Alena, you have the start right, but nothing else. In particular, you choose the worse moves for black almost immediately. This much is right 1.g3! Bf3 2.Ng6, but black has two better moves than 2......Bd1. And I will just give you a hint about the end- white doesn't checkmate the cornered king, nor does he queen the g-pawn.

Alena
Alena

The first move is obvious, but after that it's more difficult. The black king is in prison.The knight can checkmate on g3 or f2.Therefore white has got two threats. They are checkmate and advance g-pawn.Black won't be able to hold the position. I enjoyed this puzzle.

V-1

1.g3! Bd1
2.Ng6 Bc2
3.Ne7 Bd1
4.Nc6 Be2
5.Nd4 Bg4
6.Nb3 Bf5
7.Nd2 Bg4
8.Nf1 Bh3
9.Ne3 Bf1
10.g4 Bd3
11.g5 Bc4
12.g6 Bd3
13.g7 Ba6
14.g8=Q Bb7
15.Nf1 Bg2
16.Ng3#

V-2

1.g3 Bf3
2.Ng6 Bd1
3.Nf8 Bb3
4.g4 Bd5
5.g5 Bc4
6.g6 Bf1
7.g7 Bh3
8.g8=Q Bf1
9.Nxe6 Bh3
10.Nc5 Bf1
11.Ne4 Be2
12.Ng3#



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