at first glance I think white is winning

Thanks mauerblume this was a great article.

Well, I think that the nut is cracked now :-)

drakepete:

Maybe it would be worth writing up this puzzle with all the various lines and explanations as a full article?

Well, I agree and perhaps I will do and post it here. If it is really a draw, it would be a big annalytic error in the official game analysis . Done by a Grandmaster 

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Nevertheless, I have looked for another idea.

If white could reach this position it may be won. The endgame after Bxh4 looks very promising. Nevertheless, I couldn`t manage it to reach this position. But maybe ...

mauerblume, thanks for a very instructive and difficult puzzle!

The drawing line I looked at 1.Ke4 Bc7 2.Bd4 a6 3.Bf6 h3 4.Kf3 Bf4 5.b5 axb5  uses the same drawing resource as your 4...Kb8. The K+B+2Ps vs K+B with distant passed pawn threat seems to be the theme of this puzzle.

I would be amazed if anyone "saw" all the intricate side variations in this position over the board :-D

At first look 1.b5 does seem a tempting move to restrain a6 and prepare for c5, b6, and I bet the majority of players would play it.  

Yet even after 1.Ke4 it is still very complex as we can see from all the analysis elimdauer, you and I have produced. And I only posted the relevant lines, there were a lot of sub-lines I considered and rejected due to draw as White/loss as Black.

Maybe it would be worth writing up this puzzle with all the various lines and explanations as a full article?

Ok, accepting that black has to play 4. ... Kb8 this could be forced  in the 1. Ke4 without a5-line till here. Tobe honest, I haven`t found a forced winning way from this postion after 6. ... Bf4 till yet

elimdauer

I think,  In the variation 1. Ke4 without a5 I think Black is forced to play 4. ...Kb8. Otherwise 5. Ba7!will decide more or less directly

So, it seems to be clear that 1. Ke4 is the only chance to play for win. The white king has to control the h-pawn. And bishop and queenside pawns have to organize a breakthrough on their own.

The variation devides into with or without a5. So first with a5

So, it´s time for the solution, I guess!

First of all, thanks for the intersting discussions and engine-free analysis!

Well, i start with the game continuation. It was a clear forced draw.

I put together this huge analysis of Ke4 with Bd4, but the chess.com servers decided to throw it away.  So sad.

I think Ke4 is winning.  The plan is Bd4 and advancing the pawns.  Against the black plan of a6, axb5 and Kc7 trying to blockade, white will setup Be5+.  If the black bishop is on d8, white can always triangulate with the king to pass the move to black and force Be7, where now Kd5! is winning for white.  We answer Bd6 (stopping Be5+) with b6+, forcing back the king and even letting us play Ke4 again.  If black instead tries h3, then Be5+ forces back the king and controls h2, leaving the white king free to help the pawns promote.

Sorry all the pretty lines were lost, hopefully this explains it.  If anybody has a specific system of defense for black, let me know.

ps. if black does not trade with axb5, then there is no fortress with Kc7 (due to Be5+) and white advances the 3 pawns fairly easily.  The bishop stays on the long diagonal to control a1 while the king stays on e4 to guard the h pawn. 

mauerblume, how about this

I have a line that looks promising:

1.Ke4 Bc7 2.Bd4 a6 3.Bf6 h3 4.Kf3 Bf4 5.b5 a5 6.b6 a4 7.Be7 Be5 8.Ba3 Bf4 9.c5 Be5 10.c7 Bf4 11.c6 Be5 12.Be7 Bxc7 13.bxc7 Kxc7  

now White can clean up e.g. 14.Kg3 Kxc7 15.Kxh3 Kxc6 16.Bxg5 and g pawn will queen

However, I cannot find a White answer if Black plays  5...axb5

1.Ke4 Bc7 2.Bd4 a6 3.Bf6 h3 4.Kf3 Bf4 5.b5 axb5 6.cxb Kc7 and I cannot make progress

Next clue?

Love it!!! Nice one mauerblome!!!

drakepete:

2... h3 will be answered with 3.Kf3!, not with 3.Bg1

The idea of 1. Ke4 is that the king should control the dangeroush h-pawn. The Bd4 and the queenside pawns have to do the breakthrough there alone. But how?

@mauerblume 

1.b5 Bc7 2.Bd4 h3 3.Bg1

3...a5 4.bxa6 Kb8 5.a7+ Ka8 6.Ke6 h2 7.Bxh2 Bxh2 8.Kd7 Kxa7 9.c7 Bxc7 10.Kxc7 and the c pawn will queen

but what about

3...h2 4.Bxh2 Bxh2 

isn't that drawing?

With 1.b5 there's always possibility to black to play 1...Ba5 and it's draw again.

The answer is clearly to avoid exchanging bishops. So the first moves must be 1.Ke4 Bc7. 2.Bd4. The plan would be to place the White pawns on b6 and g6, and then charge forward with the King.

So, let me give you a hint.

After 1. Ke4 a5!? 2. b5 Lc7 a white win is claimed after 3. Bd4! in the annotations of the game. And as far as I have proved it this is correct.

yes drake I agree, I can't find anything for white after 1.Ke4.

I'm stumped.  Looking forward to the solution.

@elindauer 1.Ke4 a5 then 2.b5 Bc7 or 2.bxa5 Bxa5