d5 to a8

I don't see how this is a sure win. What prevents the following from happening?

1. Qf7+ Kxf7 2. c5+ Ke7! 3. cxD6+ KxD6

A queen and well-positioned pawn for a queen and a knight, leaving white down a pawn with only a bishop to work with. Could end in a stalemate....

Am I missing something?

What's wrong with 1)Qb7 ... 2)cb6 ...? Looks like a winner to me..

Well, Im only a 1600 player and I've had 3 beers, but I immediately saw 1. Qxf7+ Kxf7 2. c5+ Ke7 3. c5xd6+ Kxd6 and it seems like white should pull off the endgame with the extra bishop. If the Queen blocks on c6 the bishop takes and the black king must chase the passed c pawn.

I never got rated higher than 1352 -- and I've had more than three beers -- so technically, I guess I should just shut my gob. But black still seems alive at this point, to me. The black king is out and about, and can handle those pawns.

1. pc5 + pxc5
2. pxc5 + Qxc5
3. Qxf7

Am I missing something?

Yes in your line white is in effect two pawns up while black has no significant counterplay

But black still seems alive at this point, to me. The black king is out and about, and can handle those pawns.

The problem for black is that the extra pawn is an outside passer and can be used to keep him away from the kingside while white captures the pawns there. If white already had a passer on the kingside things would be different. I'm certainly not an expert my highest rating in the 1900's but an outside passed pawn is almost always decisive.

What's wrong with 1)Qb7 ... 2)cb6 ...? Looks like a winner to me..

Well Qd2 creates complications. Black will soon have at least a perpetual check if white continues to attack. There is no reason to complicate what is already won.

aaron black can interpose his Queen on e6 saving the piece but then as in the game White gains the outside passer that with careful play should win.

My first thought was c4 - c5, but that might not work out as well.

very nice.

Actually, I think beginning the sequence with c4 - c5 is the best move.

It probably would play-out something like this:

1. c5 + Qc7
2. Qxf7+ Qxf7
3. Bxf7+ Kxf7
4. cxb6

leaves a path for the white pawn to be promoted without challenge from the black queen.

I mean black king

I mean black king

I think you're right. During the game I looked at c5 and thought 1. c5 Qxd5 2. Bxd5 bxc5 3. bxc5 and thought the Knight could defend but Nd8 4. c6 and it's over. During the game I felt sure that the win was fairly straight forward after the line I played and so didn't analyze the other line carefully it looks like it's even better.

I'm probably missing something obvious, but how is the above a winning solution? For example, building on the steps described...

1. a4 .. Kc6
2. a5 .. h6 (or whatever)
3. b5 .. Kb7
4. bxa6 .. Kxa6
5. ...from this point on the black king has locked up his side of the board (neither white pawn can advance safely), and on the other side black has four pawns to white's three.

In other words, it is far from clear to me that white will win given the solution you described above. Could you elaborate for the slow people in the audience (i.e. me)?

Well it's typical of endings with an outside passed pawn. The fact that Black can't defend his Kingside pawns is the key. White doesn't play your suggested b5 but rather goes after the Kingside pawns. For example he might play f3.

Here is the actual game continuation after a4 it will give you a rough idea of how to win.

1. a4 g5 41. Kf1 h5 42. Ke2 Kc6 43. a5 Kb7 44. Kd3 Kc6 45. Kc4 h4 46. Kc3 Kb7
2. f3 Kc6 48. Kc4 Kd6 49. b7 Kc7 50. b8=Q+ Kxb8 51. Kd5 f4 52. Kxe5

The strategic overview of what's going on is that the black king is compelled to remain in the upper left quadrant of the board in order to prevent white from promoting its "passed" pawn.

Meanwhile the white king with its 3 pawns, cleans-up the 4 black pawns on the other side of the board - if necessary the King then moves over to assist on the other side of the board (Kc4 ..., b5).

Both c5 and Qf7 are winning moves.

take that Kc4 back - you'd have to move Kc5.

Ok, well that makes sense....

Thanks!