Not so Easy

Yesterday, I posted a position on Facebook from a game played online. In that position, my opponent blundered and lost. But, had my opponent played differently, I would have lost. The position generated a fair amount of discussion. I am particularly grateful to three commentators--Lukas Bratcher, Chris Kalina, and Misha de Rue. All three regularly comment.

We begin eighteen moves prior to the posted diagram in order to show several missed opportunities by both contestants as they played too fast with too little analysis. I was White.

White to move

Black has captured my rook on c5. I correctly assessed that my passed c-pawn could win, but missed some of the details.

33.dxc5??

It was necessary to first divert Black's king away from my e-pawn.

33.g4+ Kg5 34.dxc5+-

33.Bd3+ Kg5 34.dxc5+-

33...Kxe5-/+

Now, Black has an edge.

34.b4 g5 35.Bf3 f6 36.Bh5 h6 37.Be8 f5?

37...d4+ 38.Kd2-/+

38.Bc6

38.c6 d4+ 39.Kd2 Kd5 40.Ke2-/= Black is slightly better, but it is unclear how to make progress due to the c-pawn threatening to advance.

38...Bc8 39.Be8 f4+

39...d4+-/+

40.gxf4+ gxf4+ 41.Kf3= d4

White to move

42.Bg6??

I may have been overconfident, thinking I was better. Or, I may have believed that my bishop was needed for defense.

42.c6=

42...Bb7+ Black has the edge, but there was a stronger move.

42...Bd7-+

43.Kf2 f3 44.Bh5

Black to move

44...Kf4

44...d3 is the only move that clearly maintains Black's advantage 45.Ke3 f2 46.Kxf2 Kd4-+

45.Be8 Ke4??

45...d3=

46.Bg6+??

46.c6+-

46...Kf4= 47.Bd3??

47.Be8=

47...h5

Black missed another opportunity to put White away.

47...Be4 48.Bxe4 Kxe4 49.c6 d3 50.c7 d2 51.c8Q d1Q oh boy! White hopes to draw with perpetual checks, but Black's king can hide among the forest of pawns on the queenside.

48.Bg6 h4 49.h3

49.Be8 (only move) holds out some hope of equality, but Black remains better.

49...Ke5-+

49...Bc8-+

50.Be8 d3 51.c6

The position I posted on Facebook

Black to move

51...Bxc6??

The losing move, also suggested by a Facebook member. If Black considered the consequences of this move, he may have thought to saddle me with an unpromotable h-pawn (wrong bishop does not control h8). 

51...Ba8-/+ Black retains an edge.
51...Bc8! and Black will win. 52.Kxf3 (52.Bd7 d2 "Black wins the race." Chris Kalina)

Black to move

Analysis diagram after 51...Bc8 52.Kxf3

52...Bxh3

(Misha de Rue pointed out other ways for Black to win from this position: 52...Kd4 53.Kf2 Kc3 54.Bh5 Kc2 [or 54...d2; or 54...Bxh3] )

53.Bd7 was suggested with the belief that Black blundered in taking the h-pawn. 53...d2 54.Ke2 Be6!

White to move

Analysis diagram after 54...Be6!

I think this move solves the problems perceived in the analysis that saw 52...Bxh3 as an error.

51...d2 was also suggested, but 52.cxb7 d1Q 53.b8Q+ with an extra bishop and an exposed Black king, White should win easily. 53...Ke6 54.Qb6+ Ke7 (54...Qd6 55.Qxd6+ Kxd6 56.Kxf3+-) 55.Qe3+ Kf8 56.Bg6+-.

52.Bxc6+-

Black to move

52...Kd4 53.Bxf3 Kc3 54.Ke3 Kb2 55.Kxd3 Kxa3 56.Kc3

Here my opponent thought for a full minute. I suspect it is now dawning upon him that the game is lost.

56...a5 57.bxa5 b4+ 58.Kd2 b3 59.a6

White won by resignation 1-0

Both my opponent and I have some things that we can learn from how we played this ending.