Engines with a tactical mode/parameter

[Marek Soszynski]

Which engines have a tactical mode/parameter?
I know Houdini 4 does.
Others?

[Dann Corbit]

Which engines have a tactical mode/parameter?
I know Houdini 4 does.
Others?

For other engines, we see a tactical build rather than a tactical mode.
An example is the tactical version of Stockfish:
https://github.com/jhellis3/Stockfish/tree/mate_finder

There was also a tactical version of Rybka. It would simply do a zero window search one quarter pawn above the high water mark to try to find winning moves.

There were some others I cannot think of right now.

[Eelco de Groot]

Which engines have a tactical mode/parameter?
I know Houdini 4 does.
Others?

I am hoping for a new tactical mode Houdini that can eyeball Babson tasks.

Hi Dann, thanks for your support.

I'm working on the Tactical Mode right now.
It's not easy to reach the same level as the Tactical mode of Houdini 3 and Houdini 4. Houdini 3 is relatively the strongest tactician (relatively meaning "compared to its strength"). After Houdini 3 the strength improvements have actually made the engine less tactical.

I'm trying to make the "Tactical Mode" compatible with normal search, so that you can run, say, 5 threads with normal search combined with 1 thread in Tactical Mode.
Maybe I can get this operational for the TCEC superfinals .

Cheers,
Robert

For other engines, we see a tactical build rather than a tactical mode.
An example is the tactical version of Stockfish:
https://github.com/jhellis3/Stockfish/tree/mate_finder

There was also a tactical version of Rybka. It would simply do a zero window search one quarter pawn above the high water mark to try to find winning moves.

I'm trying to do something like this at the moment, like Rybka, but only if a secondary move in a cutoff node already failed high in the exclusion search. So I think this actually happens more in specific cut off nodes where the moves are very close together, i.e. in 'positional' nodes. As I'm using a much smaller fraction of a pawn than Ryka's ¼, the effect, I hope, is actually a bit more trying to stimulate positional fail highs, not tactical. Maybe it's too expensive to do this in game mode, but in analysis mode it should not hurt, unless by some unforeseen effects.

There is no big effect on the bench number, these three are closely related, but 016 is the standard without the 'Rybka 4 positional search' . Maybe 024 is too expensive as the node count goes up a bit:

Engine: Rainbow Serpent 20160903_016
Based on 20160903_002 MP
===========================
Total time (ms) : 4202
Nodes searched : 8959776
Nodes/second : 2132264

Engine: Rainbow Serpent 20160903_023
Based on 20160903_002 MP
===========================
Total time (ms) : 4284
Nodes searched : 8794956
Nodes/second : 2052977

Engine: Rainbow Serpent 20160903_024
Based on 20160903_002 MP
===========================
Total time (ms) : 4594
Nodes searched : 9132330
Nodes/second : 1987882

I am a bit worried though because the Rybka 4 search (just a working name) is done recursively, so in theory you could get searches many fractions of a pawn above beta going nearer the horizon, and the tree could even explode. But so far I have not seen that, and because I also built in a reduction, maybe the two cancel out. The reduction also seems much too risky at first glance...

There is always a layer of ALL nodes between any CUT node layer with the Singular Extensions/Rybka 4 positional search, so that also helps dampening explosions I think the 023 is close enough to the 016 that I can make this just a standard feature and release this version in a while. The poster of the "Stockfish is Blind" position (FishCooking, I think it was him, but I don't know if he knows this forum, all these pseudonyms make it difficult to recognize real people sometimes) asked for a release and I have not answered his request or his email even for several weeks now, did not get round to it. Probably he has forgotten but I think I will release anyhow I have not updated to Stockfish 8 yet, because that would take some testing.

There were some others I cannot think of right now.

[BrendanJNorman]

Which engines have a tactical mode/parameter?
I know Houdini 4 does.
Others?

Ktulu has "tactical factor", Deep Junior has "favor sacrifices", Prodeo has "Anti-GM mode", the recent Komodo/s have a "dynamism" setting, Thinker has dedicated builds for aggression/anti-human play, Chesstiger has "gambit" mode, Rhetoric (from version 1.4.1) has a "material" guage.... I guess there are heaps.

These settings I mentioned might all be (and I'd assume they are) worlds different at the programming level (I'd have no idea about this), but on a practical level and in terms of the overall chess, the playing style is effected in more or less the same way.