134      

126

123            

Etch wrote on 03/03/11 at 16:26:27:

I totally didn't consider Black going for check

might give it another look if I get time this evening

if Tower checks, is there a way for Black to certainly win using a Tower+King or Tower+Horse(?) combo?

you could move the King to the right and stall for some time, while moving the small thingys towards the top?

I'm just having fun trying to understand this pro level puzzle, please bear with me

124.

TvL: I'd like to give the problem ago, so don't post the solution just yet (although I haven't played for years). My instinct is 2. b7 for the next move.

Edit: actually, I'm confused by the description - you say in move 3 Black has a defensive try, but isn't move 3 White's?

Darius wrote on 03/04/11 at 05:40:55:

Usually in chess, when counting moves, a move from White and subsequent move by Black are together counted as one move. For example, when it is said that a game lasted 30 moves, there were 30 moves from White and 30 (or 29) from Black. So when I say "Black ... on move 3", I mean "on Black's 3rd move".

Basically, the solution looks like this:

1.	Rh7-c7	Rc8-b8
2.	...!	...
3.	...	...!
4.	...!!	...
5.	...	...
6.	...!	...
7.	...	...
8.	...

The exclamation marks indicate good / hard-to-see moves.
In addition, there are variations: some alternative moves for Black are shown to be insufficient as well, and some alternatives for White are shown to be not winning.
I should note that after White's 6th move, the win is already pretty evident. Black's 6th and 7th move are objectively speaking not best, but do require White to play the only move (but they're quite trivial).

After 2.Rb7, 2...Ne6 is hardly a test for White; 3.Rxb8 wins easily. But what would happen after 2...Nxb7? Or 2...Ra8? Or 2...Rc8?


On topic: I'll take a stab at 346

I've had a thought: 2. Rc8? I think Rxc8 for Black leads to 3. b7 Nxb7 4. axb7 Rb8 5. c6 leaves Black in an impossible position, so I would say Black would have to find another way out.

^ You're missing 146

@Darius: 2.Rc8? Rxc8 3.b7 Nxb7 4.axb7 Rxc5+ (check!) 5.Kd2 Rb5 even wins for Black.

TvL wrote on 03/05/11 at 07:22:52:


Ah, forgot about the check. I really do need to start playing again. I'm certain that it's not 2. c6 because Rxb6 pretty much finishes White's chances in one go.

Etch has made me think that maybe Rb7 is the right opening. Anything from Rf8-h8 from Black leaves open the possibility of a series of checks, but that's just a temporary stall as White will get the opportunity to play a8Q and ultimately prevent the rook from checking the king. 3....Rc8 threatens 4....Rxc5+ and an endless back of forth. What about 3. c6 to bring the third pawn in as a threat? That leaves Black open to play axb6 but White could follow with axb7 or cxb7, so perhaps this is when Black needs to play Rc8...maybe it's c7 from White, putting the rook under threat from the b-pawn if the next move was Rxc7.

2. Rb7 Nxb7
3. c6 Rc8
4. c7 axb6
5. axb7

I don't see what Black's rook can do after this because both pawns are now covering each other - it has to move because it's under threat, but Rxc7 leads to b8Q, all of a8-d8 are unavailable and a move to e8-f8 simply allows either b8Q or c8Q, with the other pawn covering the promoted piece. 6 is supposed to be an unusual/strong move, and I don't see how simply promoting to queen is classified as either of those. So maybe after 4. c7, Black plays Nd6 to cover c8, which probably leads to 5. b7. Now, I don't think Black has to worry about the rook here, because if 6. bxc8 Nxc8 then both pawns are blocked and it's stalemate. Does that mean the answer is Black plays something like Rd4 and White needs to sacrifice one promoted pawn by playing 6. b8Q+ Rxb8 then 7. cxb8Q+ leaves Black with little options other than something like Kd4 and White can pick off the knight with 8. Qxd6. Perhaps I'm missing something again, though.

All right I'll guess again.

I'll go with 146, part of Shock's master plan to not include it at first?  

Shock wrote on 03/05/11 at 07:08:20: