Thx Girkassa,Glenn Snow
@Girkassa
Wel spotted the error in the side-line, I have corrected it.

@Glenn Snow:
Yep: if the bishop had been at c2 at the start the position is won for White. He would play 61.Bb3!
And now: 61...Kd6 no longer draws (see variation B1),
since at the critical moment White can defend a pawn on h5 with his bishop.
In fact after 61.Bb3,Kd6 62.Kg6 we have the same position as after 64.Bb3 in variation B1.

while 61.....Kd8 62.Be6 also wins (also see variation B1)

White also wins if the bishop had been at a2 at the start.

Thanks for an excellent presentation (as usual)! Following the game on ICC, most kibitzers called the endgame either an easy win or an easy draw, while in reality neither group were entirely right. I must confess I thought the position was a rather easy draw as I missed the 61.Ba2! idea.

BTW, there is a mistake in your last post. In the 61...Kd8 line, after 62.Be6 Be7 you give 63.g5, which is of course impossible since White's king is still on f7. I am sure you meant to give the line 63.Kg6 Ke8 64.g5 Kf8 65.h4 which is winning.

B) Kramnik - Aronian, White plays 61.Ba2!

This move as will become apparent, in fact prepares g5 since with the extra tempo, Black can no longer safely sack his bishop on g5. (Remember the lost position I showed with a bishop of the wrong color in the first post on basic knowledge).

Black has basically two choices:
61....      Kd8
61.      Kd6 (Aronians move)

B1....      61...Kd8 is no longer sufficient

Actually Arionans continuation 61....Kd6 was the only drawing move!

61.....            Kd8?
62.Be6!            



Now  the bishop moves 62....Bf2 and Be1 loose right away:
63.g5, Bc3 64.g6 and after the inevitable 65.g7,Bxg7 66.Kxg7 the h-pawn promotes
Which leaves us with two candidate moves:

The other bishop move available: 62....Be7 also loses quickly
62...Be7 63.Ke6, Ke8  64.g5,Kf8 and the pawns roll on unhindered. Note that in this variation 64...Bxg5 loses since blacks king is cut off (65.Kxg5,Ke7 66.Ba2,Kf6 67.Kg6)

62.      Kc7!
63.Kg6      Kd6
64.Bb3

Note that this position differs from the position in the game only in one respect. White's bishop is no longer on a2, but is now on b3. This seemingly unimportant difference, is result changing as we will see.

64.            Ke5
The only plan left, since Black is unable to get his king in front of the pawns.
65.Kh5      Be7
66.h4            Kf4
On 66...Kf6 67.Kh6 decides the game quickly, so black targets the h-pawn. Trying to tie the white king to its defense.
67.g5      Kg3
68.g6!!      Bf8



It is not immediately obvious how white can make progress. And Black threatens Kf4 with an immediate draw, with essentially the final position in the game.

69.Kg5!!      Be7+
Otherwise h4-h5 etc
70.Kf5!
The only way to a win. 70.Kh6,Bf8+ 71.Kg5 (71.Kh5? Kf4=) and white has made no progress.
70.      Bf8
71.h5            Kh4

72.Bd1!
The essential difference with the game. There the bishop was on a2, so white could not protect his pawn on h5. Now it is all over. 



Black cannot prevent a plan involving Kf6 and g6-g7: 72...Bg7 73.Be2,Bf8 (73...K? 74.Kg5 followed by h6) 74.Kf6 +-

B2 The actual game continuation 61.Ba2,Kd6!
Actually 61....Kd6!! is the only move that draws



61.Ba2      Kd6!!
The only way to draw.
62.Kg6      
I did some analysis on 62.Bb3,Ke5 63.Kg6 only to conclude that Black can use his extra tempo to draw comfortable with 63....Kf4.
62.      Ke5
63.Kh5      Be7
64.g5
64.h4, Kf4 65.g5,Kg3 transposes back into the game
64      Kf4
65.h4
65.g6,Bf8 draws immediately since it imprisons white king.
65.      Kg3



The winning method of B1 does not work:
66.g6,Bf8 67.Kg5,Be7+ 68.Kf5,Bf8 69.h5,Kh4 and whites pawns are gonna drop.
Therefore Kramnik sets a last trap

66.Bc4!,
With the same idea as variation B1
66......., Bf8!
Again the only drawing move:
66....Kh3? 67.g6! And now white wins as in variation B1
66....Bd8? 67.g6, Bf6 68.Bf1! , Kf4 (68...Bg7 69.Kg5 +-) 69.Kh6 +- (with h5 and eventually g7 to follow)
67.g6      
Kramniks agrees to a draw. Note that
67.Bb3 is now answered by ....,Bg7! 68.Kg8,Kxh4!
67......Kf4!=
And as we saw already in several variations White's king is trapped. There is no progress to be made. Black simply keeps peddling his bishop between f8 and g7.

C White plays 61.Bc2 iso 61.Ba2
Actually you should be able to work this one out for yourself using the previous variations.....

61.Bc2 is a slightly devious move. 
After 61.Bc2,Kd6 62.Kg6, Black once again would have to find an only move to draw. Ke7! =
Now 62...Ke5 would lose, since White has again found the extra tempo he needed to win as in variation B1.
However with the Bishop not on the a2-g8 diagonal, Black can employ a plan as illustrated in variation A2 Without the bishop on the a2-g8 diagonal,  black can answer g5 with Bxg5 and should draw without difficulty

Summary
In this endgame Black had several drawing strategies:
-  Producing a position where white could no longer make progress.
---> Binding the white king to the defense of the pawns
--->  Blockading he pawns on the Black squares
-  Sacking his bishop against the g-pawn leaving 
-  Sacking the bishop for both pawns.

Kramnik produced a winning attempt, using basic knowledge that not all endgames with h-Pawn + bishop of the wrong color are drawn!

As it turned out, he was only one tempo short of a win.

Kramnik-Aronian, Candidate Tournamen, round 5



In the diagram position white has 3 options:
(A) 61.Kg6 (B) 61. Ba2,as Kramnik played (C) 61.Bc2.


A) The direct approach, 61.Kg6

61.Kg6 is actually the easiest move to deal with from Black points of view. All king moves that bring blacks king closer to the kingside draw (Ke8,Ke7,Ke6). The only thing Black can not afford is to play a bishop move.

We first illustrate the fact that at this point bishop moves will lose:

A1 61.Kg6:  Black cannot afford bishop moves

61.Kg6      Be7?
62.g5!      
Now Black can not sack his bishop, since after 62...Bxg5 63.Kxg5,Ke7 64.Kg6,Kf8 65.Ba2!
We have diagram 1 where white is winning despite his bishop of the wrong color.

62.      Ke8 (too late)
63.h4      
Rules out any sack at all.
63....      Kf8
64.Kh7!
64.Ba2 wins as well
64      Be7
65.g6      
Here it is. White can safely play this since Black is no longer able to establish a blockade on the black squares.


In the diagram there is nothing black can do against Ba2-h5-h6-g7+ winning.

A2  Black plays 61.Kg6,Ke8!



To make any progress at all, White at some point will have to play Kg6-h5 to break the blockade on h4.
It should be noted that 62.g5 is no use now: 62...Bxg5 63.Kxg5,Kf8 immediately secures the draw.
If white plays a bishop move Blacks king continues his journey to the king side with Ke8-f8.

62.Kh5, Be7
63.h4
If Kg6 or Kh6 Black simply resumes his blockade with Bh4. And a bishop move like Ba2 is once again answered with Kf8.
63.      Kf8!
64.g5
The only way to make any progress at all, since the King is otherwise bound to the defense of the h-pawn.
And 64.h4 allows Bxg5=
64....      Kg7
65.Kg4, Bd8
Black also draws with 65...Bb4 66.Kf5,Bd2 as illustrated In the preliminary positions. 
66.Kf5,Be7



67.Ke6
Note that 67.h5 is again answered by Bxg5=, while g6? Bxh4 draw at once.
67.....      Bd8
67...Bb4 is sufficient for a draw as well: 68.Kf5,Bd2= As shown in the preliminary position  69.h6+,Kh8!=
68.Kd7,  Bb6
At least drives the bishop away from the d8-h4 diagonal. But the unsupported pawns form no threat for Black.
69. h5,        Be3!
70. h6+,       Kh8=
And after  70.g6 the pawns are securely blockaded, since Black keeps his bishop on the c1-h6 diagonal. But any other move drops either the g or the h-pawn.

My next post will deal with what was actually played.
Of course I will also post a pgn-file.