Simple mate in 6 that gives some engines trouble

[Dann Corbit]

acn 883293; acs 2; bm Nh6; ce 32756; dm 6; pv Nh6 gxh6 Re5 dxe5 Qf6+ exf6 Ne3 dxe3 Rf5 g1=Q Rh5#;

[camava]

Hi mr Dann Corbit.You are right,Komodo 12,..stockfis 10,..Houdini 5 pro,..booot 6.3..,Fizbo2.0,...Rybka4,..Andscacs,..all they are powerfull engines and they could not find mate in 5 minutes that i was test them.But Critter1.6a,..Cheese 20...Counter_v3.2...DeepSaros4.16...IvanHoe9.46f...MateFinder10...Octochessr5190 and Spark 1.0 found Mate#6 in less than 5 seconds!.
Now i think this is because they have this position in some datebase.I had having same situation with other positions,that is strange for me.

[camava]

Hi mr Dann Corbit.You are right,Komodo 12,..stockfis 10,..Houdini 5 pro,..booot 6.3..,Fizbo2.0,...Rybka4,..Andscacs,..all they are powerfull engines and they could not find mate in 5 minutes that i was test them.But Critter1.6a,..Cheese 20...Counter_v3.2...DeepSaros4.16...IvanHoe9.46f...MateFinder10...Octochessr5190 and Spark 1.0 found Mate#6 in less than 5 seconds!.
Now i think this is because they have this position in some datebase.I had having same situation with other positions,that is strange for me.

I was forgeting about Pedone and Murka,they found Mate#6 after 1 minute

[rcmaddox]

Deep HIARCS 14 announces the mate either instantly or in a few seconds.

[Dann Corbit]

I think the problem is null move pruning found in the strongest engines.
If you look at the pv, they give up 3 pieces in succession, including the queen!
Now, it is just a 12 ply combination. So it ought to be real simple.
But heavy pruning can push it way off into the distance.

[chessmobile]

Hiarcs gets it fast

[rcmaddox]

I couldn't get Komodo 11.2.2 to solve this mate at all. But Komodo 4 solves it in under 3 minutes.

[duncan]

acn 883293; acs 2; bm Nh6; ce 32756; dm 6; pv Nh6 gxh6 Re5 dxe5 Qf6+ exf6 Ne3 dxe3 Rf5 g1=Q Rh5#;

Crafty takes a few seconds

[xr_a_y]

Pretty one !
Minic needs "mateFinder" mode to get this one :

Code: Select all

12 9988 4321 109174781 32 2526 10621	g8h6 g7h6 e2e5 d6e5 b6f6 e7f6 d1e3 d4e3 f4f5 g2g1q f5h5 

[elcabesa]

Vajolet finally found it after 45 minutes