Does any engine find a5 in this position?

[Uri]

Does any engine find the move 15...a5 in this position? I don't know if it's the best move but a5 seems to me the attacking move in this position. All the other moves are quite passive or defensive.

[d]2rq1rk1/3bppbp/p2p1np1/7P/1n1NP1P1/2N1BP2/1PPQ4/1K1R1B1R b - - 0 15[d]

I let Rybka 3 32 bit think for 10 hours on this position and it gives this...

Analysis by Rybka 3 32-bit:

1. ± (0.94): 15...Re8 16.hxg6 fxg6
2. ± (0.96): 15...Bh8 16.hxg6 fxg6

Rybka 3 64 bit is 2 times stronger than 32 bit so the 64 bit version may find this move eventually.

[Terry McCracken]

Does any engine find the move 15...a5 in this position? I don't know if it's the best move but a5 seems to me the attacking move in this position. All the other moves are quite passive or defensive.

[d]2rq1rk1/3bppbp/p2p1np1/7P/1n1NP1P1/2N1BP2/1PPQ4/1K1R1B1R b - - 0 15[d]

I let Rybka 3 32 bit think for 10 hours on this position and it gives this...

Analysis by Rybka 3 32-bit:

1. ± (0.94): 15...Re8 16.hxg6 fxg6
2. ± (0.96): 15...Bh8 16.hxg6 fxg6

Rybka 3 64 bit is 2 times stronger than 32 bit so the 64 bit version may find this move eventually.

The hardware might be two times stronger but not Rybka going from 32bit to 64bit.

The programs are similar in strength but the 64bit ver. can use 64bit registers and compute the answer 40 to 60 precent faster.

a5 is easy so Rybka has a problem in "understanding" this position.

[michiguel]

Does any engine find the move 15...a5 in this position? I don't know if it's the best move but a5 seems to me the attacking move in this position. All the other moves are quite passive or defensive.

[d]2rq1rk1/3bppbp/p2p1np1/7P/1n1NP1P1/2N1BP2/1PPQ4/1K1R1B1R b - - 0 15[d]

I let Rybka 3 32 bit think for 10 hours on this position and it gives this...

Analysis by Rybka 3 32-bit:

1. ± (0.94): 15...Re8 16.hxg6 fxg6
2. ± (0.96): 15...Bh8 16.hxg6 fxg6

Rybka 3 64 bit is 2 times stronger than 32 bit so the 64 bit version may find this move eventually.

The hardware might be two times stronger but not Rybka going from 32bit to 64bit.

The programs are similar in strength but the 64bit ver. can use 64bit registers and compute the answer 40 to 60 precent faster.

a5 is easy so Rybka has a problem in "understanding" this position.

I think Rybka is correct. Re8 sounds like a reasonable move in this position.
The other potential move is Qa5, which I think is better than a5.

Miguel

[ernest]

The hardware might be two times stronger but not Rybka going from 32bit to 64bit.

Depends on the position:
On the start_position, Rybka3_64bit is x1.73 faster than Rybka3_32bit (Rybka232a_64bit was even x1.86 faster than Rybka232a_32bit).
For endgames, you might get only x1.4 to x1.5

[Terry McCracken]

Does any engine find the move 15...a5 in this position? I don't know if it's the best move but a5 seems to me the attacking move in this position. All the other moves are quite passive or defensive.

[d]2rq1rk1/3bppbp/p2p1np1/7P/1n1NP1P1/2N1BP2/1PPQ4/1K1R1B1R b - - 0 15[d]

I let Rybka 3 32 bit think for 10 hours on this position and it gives this...

Analysis by Rybka 3 32-bit:

1. ± (0.94): 15...Re8 16.hxg6 fxg6
2. ± (0.96): 15...Bh8 16.hxg6 fxg6

Rybka 3 64 bit is 2 times stronger than 32 bit so the 64 bit version may find this move eventually.

The hardware might be two times stronger but not Rybka going from 32bit to 64bit.

The programs are similar in strength but the 64bit ver. can use 64bit registers and compute the answer 40 to 60 precent faster.

a5 is easy so Rybka has a problem in "understanding" this position.

I think Rybka is correct. Re8 sounds like a reasonable move in this position.
The other potential move is Qa5, which I think is better than a5.

Miguel

Actually after giving the postion a second look I think all 3 are good but Re8 to be best, maybe, followed up with a5 and Qa5, but I'd have to really look at it to see if Qa5 after Re8 is better than a5.

I think Rybka does indeed "understand" the position! Bravo!

[playjunior]

I didn't have a look with an engine but ...a5 looks weak to me.
...Re8 is a solid move, it creates some room for the King to flight, also the bishop can retreat to f8 in some variations I guess. Qa5 might work against a human but I wouldn't be surprised if an engine refutes it by a forced 24-move line.

Overall white looks fine.

[michiguel]

I didn't have a look with an engine but ...a5 looks weak to me.
...Re8 is a solid move, it creates some room for the King to flight, also the bishop can retreat to f8 in some variations I guess. Qa5 might work against a human but I wouldn't be surprised if an engine refutes it by a forced 24-move line.

Overall white looks fine.

The idea of Re8 is to retreat the Bishop to h8 to avoid exchanging bishops if white plays Bh6.

Miguel

[Terry McCracken]

I didn't have a look with an engine but ...a5 looks weak to me.
...Re8 is a solid move, it creates some room for the King to flight, also the bishop can retreat to f8 in some variations I guess. Qa5 might work against a human but I wouldn't be surprised if an engine refutes it by a forced 24-move line.

Overall white looks fine.

The idea of Re8 is to retreat the Bishop to h8 to avoid exchanging bishops if white plays Bh6.

Miguel

Of course! And I think it's the best move. Then it's time to exploit White's weak a-file and both Qa5 and a5 come to mind. After Re8 a5 isn't weak and Qa5 is commonly played. But I know you're a very strong player. I think the fellow you're repling to overrates White's position and feels it safe but it's not!

Infact a, b, and c files are open to attack while White has space and the h-file to exploit and it may not be enough...these double-edged positions are very tricky and in this case I see a Black advantage.

[Terry McCracken]

The hardware might be two times stronger but not Rybka going from 32bit to 64bit.

Depends on the position:
On the start_position, Rybka3_64bit is x1.73 faster than Rybka3_32bit (Rybka232a_64bit was even x1.86 faster than Rybka232a_32bit).
For endgames, you might get only x1.4 to x1.5

Even if you get twice the speed it doesn't equate as twice as strong. That was my point.

[michiguel]

I didn't have a look with an engine but ...a5 looks weak to me.
...Re8 is a solid move, it creates some room for the King to flight, also the bishop can retreat to f8 in some variations I guess. Qa5 might work against a human but I wouldn't be surprised if an engine refutes it by a forced 24-move line.

Overall white looks fine.

The idea of Re8 is to retreat the Bishop to h8 to avoid exchanging bishops if white plays Bh6.

Miguel

Of course! And I think it's the best move. Then it's time to exploit White's weak a-file and both Qa5 and a5 come to mind. After Re8 a5 isn't weak and Qa5 is commonly played. But I know you're a very strong player.

Perhaps... I used to be....
Miguel

I think the fellow you're repling to overrates White's position and feels it safe but it's not!

Infact a, b, and c files are open to attack while White has space and the h-file to exploit and it may not be enough...these double-edged positions are very tricky and in this case I see a Black advantage.