The strongest passer

[lantonov]

[d]r1r1n1k1/3qbppp/1n2p3/p2pP3/1ppP1BNP/5N2/2PQBPP1/R3R1K1 w - - 0 1

Actually, black wins even easier here.

For example: Bg5 Bf8, followed by Na4-c3, and black pushes the a passer forward.

White can do nothing to prevent that.

I can't believe there are engines that do not recognize an easy win for black on the above diagram.

So, quite probably, on the original diagram, black has at least 70-80cps advantage in terms of eval at the root.

Here, SF proposes h5 or Bh6 with about a pawn advantage for white but let's go with the Bg5 line. So, Bg5 Bf8 (SF proposes a4) h5 Na4 (SF proposes b3) h6 Nc3? (SF proposes g6 +1.6) hxg7 with 4.5-5 pawns white advantage.

What if played Bh6 Line...Which forces bishops otherwise.

The other Lyudmil is the chess expert, so he will have the last word. I didn't press the matter with h5 and Bg6 because I envisaged the same strategy as on Bg5. I played some variants on this with SF trying to include the strategic moves Na4-c3, a4, Rcb8, without success. Obviously, I am not on a par with SF.

[Masta]

First position...is a win for black. The problem is that you were sacrificing a bishop first.

First sac the knight...then comes another astonishing sacrifice just to keep the pawn chain rolling.

1...Nxa4 2.bxa4 Bxa4 3.h4 Rfb8 4.h5 Bxc2 5.Qxc2 b3 6.Qb1 a4 7.h6 g6 8.Bf1 a3 9.Re2 a2

Clear win for black after a2!

CHeers.

[Masta]

First position...is a win for black. The problem is that you were sacrificing a bishop first.

First sac the knight...then comes another astonishing sacrifice just to keep the pawn chain rolling.

1...Nxa4 2.bxa4 Bxa4 3.h4 Rfb8 4.h5 Bxc2 5.Qxc2 b3 6.Qb1 a4 7.h6 g6 8.Bf1 a3 9.Re2 a2

Clear win for black after a2!

CHeers.

Well maybe not a win for black...but a second sacrifice will be needed in some point to remove the c2 pawn (I think).

[carldaman]

It is not possible, because of technical reasons. The transposition table requires to stay path independent. In TT we store a position and a value for the position, independent of the move sequence (=path) that leads to the position, hence the name transposition table. I'm not sure you understand it but it would be very important to understand this! ...OK, this was my last comment about it here in this thread.

I do understand it, now that you explained it. The same position ensues in the transposition table regardless of how you got there. Good to know.

Thanks,
CL

[Lyudmil Tsvetkov]

First position...is a win for black. The problem is that you were sacrificing a bishop first.

First sac the knight...then comes another astonishing sacrifice just to keep the pawn chain rolling.

1...Nxa4 2.bxa4 Bxa4 3.h4 Rfb8 4.h5 Bxc2 5.Qxc2 b3 6.Qb1 a4 7.h6 g6 8.Bf1 a3 9.Re2 a2

Clear win for black after a2!

CHeers.

I supposed something like that, but I can not analyse everything...

What normal person on this Earth would sacrifice 2 minor pieces, with no immediate promotion, and no immediate compensation, especially when the sparring engine is SF?

I grant I am a bit crazy myself, but still...

I guess enormous amount of calculation is required to confirm or disprove the double sacrifice.
Personally, I am not certain I can shoulder such a task.

[Lyudmil Tsvetkov]

First position...is a win for black. The problem is that you were sacrificing a bishop first.

First sac the knight...then comes another astonishing sacrifice just to keep the pawn chain rolling.

1...Nxa4 2.bxa4 Bxa4 3.h4 Rfb8 4.h5 Bxc2 5.Qxc2 b3 6.Qb1 a4 7.h6 g6 8.Bf1 a3 9.Re2 a2

Clear win for black after a2!

CHeers.

Well maybe not a win for black...but a second sacrifice will be needed in some point to remove the c2 pawn (I think).

As I said, a very difficult position, with innumerable reasonable lines.

All I am cretain is that in the initial position black is better, and that, if black does not sacrifice something on a4, white will gradually achieve advantage by attacking on the king side.

When I talked about Uri being right about sometimes calculating more plies than 120, you could refer for example to this position. In some lines I go to move 50 from the initial position/depth 100, and am still not certain if the definite solution is in sight.

[Ralph Stoesser]

I do understand it, now that you explained it. The same position ensues in the transposition table regardless of how you got there.

Right. We can't manage different scores for the same position dependent on how we get there. That would clash with how the hash table works. Therefore every idea in that direction would be in vain. That's because I assume it would be better to find ways to "tell" the engine something like this:

You have a little part of pointy chain, you still can get there, I'll give you a small bonus for this position to steer you in the right direction.

and next:

That's even better, I'lll give you more bonus for this position

and so on...

... and finally:

Good, you now have the complete pointy chain! Large bonus. Now slaughter your opponent on the king side.

Easy to write but very hard to find ways to get it right.