What are the least aggressive engines?

[chesskobra]

Among the top engines which engines score very low on EAS? By least aggressive, I don't mean solid and defensive but something that just tries to slowly suffocate the opponent, without being flashy. An engine whose main philosophy is restriction and prophylaxis. I would love to have such an engine.

Incidentally, I looked at Karpov's game (using pgn-extract filters for sacrifices) and he is on par with some of the other aggressive players like Topalov. But still I would not mind an engine that plays like Karpov. Has anybody analysed games by human players with EAS like tools?

But maybe a quest for 'styles' is futile; strong engines are the ones that play more objectively.

[BrendanJNorman]

Among the top engines which engines score very low on EAS? By least aggressive, I don't mean solid and defensive but something that just tries to slowly suffocate the opponent, without being flashy. An engine whose main philosophy is restriction and prophylaxis. I would love to have such an engine.

Incidentally, I looked at Karpov's game (using pgn-extract filters for sacrifices) and he is on par with some of the other aggressive players like Topalov. But still I would not mind an engine that plays like Karpov. Has anybody analysed games by human players with EAS like tools?

But maybe a quest for 'styles' is futile; strong engines are the ones that play more objectively.

Most likely certain Lc0 nets would suit this purpose.

But my old "Strangler" personality in Rodent III was had a very nice "boa-constrictor" style as well.

I've recently been experimenting with Komodo 14 but turning all king safety and dynamism options to 0 and using "Positional" style.

I kills some Elo admittedly, but you get a lot of very positional games.

[Whiskers]

Viridithas 14 clocks in at 36,681 EAS on Pohl's EAS-Ratinglist, the lowest I've ever seen on there. That's only about 10 times less than Patricia

[pohl4711]

Viridithas 14 clocks in at 36,681 EAS on Pohl's EAS-Ratinglist, the lowest I've ever seen on there. That's only about 10 times less than Patricia

Yes, that is a very, very small EAS-Score, so Viridithas 14 plays definitly very solid (=boring?).

[Rowen]

Among the top engines which engines score very low on EAS? By least aggressive, I don't mean solid and defensive but something that just tries to slowly suffocate the opponent, without being flashy. An engine whose main philosophy is restriction and prophylaxis. I would love to have such an engine.

Incidentally, I looked at Karpov's game (using pgn-extract filters for sacrifices) and he is on par with some of the other aggressive players like Topalov. But still I would not mind an engine that plays like Karpov. Has anybody analysed games by human players with EAS like tools?

But maybe a quest for 'styles' is futile; strong engines are the ones that play more objectively.

I found Rybka 2.3.2 a to be quite solid, maybe suffocating? waiting for the opponent to make a mistake (I remember someone comparing its' style to a shark, just waiting). It can still be downloaded from the rybka site.

[chesskobra]

I will try Komodo 14, Viriditas 14. I had not noticed that in Komodo 14 there were personalities. Rybka is windows only?

Is there a description of Komodo parameters somewhere? There are many parameters that I don't understand (selectivity, reduction, contempt, white comtempt, polyglot contempt score, MCTS explore (specified by a number), variety (related to book variety?)

[chesskobra]

I just compiled rodentIII but I don't see a way to select personalities (neither in xboard nor in cutechess-gui), but they have been installed. Xboard shows several parameters, and the personalities have values of these parameters, so in principle I can set each parameter individually as in the personalities files. Is there a straightforward way? There is a Petrosian personality, with description "defense, restraint, likes closed positions, likes sacrificing exchange".

[Rowen]

I will try Komodo 14, Viriditas 14. I had not noticed that in Komodo 14 there were personalities. Rybka is windows only?

Is there a description of Komodo parameters somewhere? There are many parameters that I don't understand (selectivity, reduction, contempt, white contempt, polyglot contempt score, MCTS explore (specified by a number), variety (related to book variety?)

I have only ever seen rybka in a windows version. I only have the free versions but if you download dragon / komodo there are descriptions there of the parameters. I have long noticed that if you set king safety and dynamism high you get an almost naïve aggression (like a strong aggressive kid), so if you do the opposite the engine may become solid ? as brendan is experimenting with.

[Sylwy]

I will try Komodo 14, Viriditas 14. I had not noticed that in Komodo 14 there were personalities. Rybka is windows only?

Is there a description of Komodo parameters somewhere? There are many parameters that I don't understand (selectivity, reduction, contempt, white contempt, polyglot contempt score, MCTS explore (specified by a number), variety (related to book variety?)

I have only ever seen rybka in a windows version. I only have the free versions but if you download dragon / komodo there are descriptions there of the parameters. I have long noticed that if you set king safety and dynamism high you get an almost naïve aggression (like a strong aggressive kid), so if you do the opposite the engine may become solid ? as brendan is experimenting with.

Deep Rybka 4.1 (latest commercial) parameters:

[tapio]

Unfortunately Viriditas 13 playing strength cannot be reduced