Does Houdini 1.5 adjust playing style to opponent?

[AnthonyTheSage]

Houdini seems to play aggressive against some engines and defensive against others. Someone mentioned to me that Houdini 1.5 changed style according to opponent. Is it just the contempt level that changes or is it other settings also? What settings does Houdini use for analysis? Also why is not recommended to use analysis contempt? Hopefully Robert has time to give me an answer but if anybody else knows thats fine too.

[Robert Houdart]

Anthony,

As far as I know Houdini doesn't adapt its playing style to the opponent.

The reason for not using "contempt_analysis" is that it produces asymmetric evaluations - the evaluations are slightly skewed in favor of the player having the move. If you would analyze a position with White, then play a move, and analyze the position with Black, you would get different evaluations.
"Contempt_analysis" can be useful if you're always analyzing the game for the same side.

Robert

[Peter C]

As far as I know Houdini doesn't adapt its playing style to the opponent.

As far as you know?
Does this mean there is some code in there that you don't know about? Like... IvanHoe code?

I trust you for the most part Mr. Houdart, but I would really like to see some proof that Houdini is original. Submitting the source to a respected programmer to analyze it would be a good start.

Peter

[Robert Houdart]

Peter,

"As far as I know" is a polite and respectful way of saying that the other person is wrong, hinting at some doubt so that the other's person's honour is safe.

On the other hand, your reaction is neither polite nor respectful, nor very relevant to this topic. Please be so kind to stop your obsession with "trust" you might have/not have in Houdini, or with "some proof" obtained from a "respected programmer" as a "good start". The chess world has moved on...

Robert

[Peterpan]

Houdini is the best modification of Ivanhoe!
Good work and viva open source

[Robert Houdart]

Peterpan, Houdini is not a "modification of Ivanhoe" nor "open source".

If every of my replies is going to be followed by an incorrect, off-topic speculation about Houdini, it becomes very difficult for me to interact efficiently with this forum.

[Jeremy Bernstein]

Peterpan, Houdini is not a "modification of Ivanhoe" nor "open source".

If every of my replies is going to be followed by an incorrect, off-topic speculation about Houdini, it becomes very difficult for me to interact efficiently with this forum.

I don't want to get in the way of your efficiency, but maybe the problem is that Houdini 1.0 produced identical evaluations as Ippolit (or Robbo, I don't remember what I tested with anymore -- I'm sure you remember the post on TalkChess) in some positions. Not similar, identical. I have a great deal of respect for you and your work, Robert, but your denial on this point is really aggravating.

For what it's worth, I think you've demonstrated a great deal of aptitude and talent in chess engine development, and I really enjoy using Houdini. Nevertheless, the origins are (justifiably) relevant for some computer chesslers.

My 2c,
Jeremy

[Prima]

Robert Houdart,

I'm not sure if this thread is the appropriate thread....but thank you for this marvelous engine.

I've noticed a positive learn-feature in Houdini either in Fritz GUI or Winboard + PolyGlot. It is easier for Fritz GUI to do book-learn/book-weight adjustments via its book-settings etc within its GUI feature. However in Winboard GUI + PolyGlot, where PolyGlot bin books/book-move-weight are pretty much fixed from the moment they're created and have no book-learn mechanism like the Fritz GUI, Houdini really shows it's learn abilities. For the most part, Houdini plays different lines as if it learned from past mistakes. I'm simply amazed.

Please keep up the good work. I wish all chess-engine authors/teams success in their endeavors.

[Robert Houdart]

I don't want to get in the way of your efficiency...

Like the two earlier replies, your reaction is completely off-topic for this thread.
It's a sad day for a forum when even the grand moderator feels the irresistible urge to make counter-productive, off-topic interventions.

[Jeremy Bernstein]

I don't want to get in the way of your efficiency...

Like the two earlier replies, your reaction is completely off-topic for this thread.
It's a sad day for a forum when even the grand moderator feels the irresistible urge to make counter-productive, off-topic interventions.

Great, I'll start a new thread then, where we can talk these issues out in a productive, on-topic fashion.

Jeremy