Fruit is already a free chess engine....

[swami]

Hi,
You can now download Fruit 2.2,2.2.1 and the strongest Beta 5 since November 2005

http://www.fruitchess.com/

Thanks to Fabien!

[swami]

I don't see anything sad in it. Fabien decided that he has more interesting things to do and he is probably happy with this decision.

When we say sad day, we don't mean sad day for Fabien but for us, since we understand that by releasing the Fruit for free, Fabien does not have the intention to make Fruit stronger. So that is a negative thing.

How do you know he won't be working on Fruit anymore?I heard that he is going to work on another chess program called chess64 or something.

[mjlef]

The 051103 version sure has a lot of knobs to fiddle with. Does anyone know what they all mean? Pawn duos seem simple enough, but what about "Hisotry Reduction 1" and "History Reduction 2" and "Move Skip 2"? If someone know what they mean, please let us know.

[Dr.Wael Deeb]

The 051103 version sure has a lot of knobs to fiddle with. Does anyone know what they all mean? Pawn duos seem simple enough, but what about "Hisotry Reduction 1" and "History Reduction 2" and "Move Skip 2"? If someone know what they mean, please let us know.

It would be nice all these settings to be documented somewhere so that we can try several personalities

[Ryan Benitez]

The 051103 version sure has a lot of knobs to fiddle with. Does anyone know what they all mean? Pawn duos seem simple enough, but what about "Hisotry Reduction 1" and "History Reduction 2" and "Move Skip 2"? If someone know what they mean, please let us know.

It would be nice all these settings to be documented somewhere so that we can try several personalities

Another newer version (maybe more than 1) will be out soon with more UCI options. I hope everyone enjoys the Fruit versions.

Thanks,
Ryan

[Dr.Wael Deeb]

The 051103 version sure has a lot of knobs to fiddle with. Does anyone know what they all mean? Pawn duos seem simple enough, but what about "Hisotry Reduction 1" and "History Reduction 2" and "Move Skip 2"? If someone know what they mean, please let us know.

It would be nice all these settings to be documented somewhere so that we can try several personalities

Another newer version (maybe more than 1) will be out soon with more UCI options. I hope everyone enjoys the Fruit versions.

Thanks,
Ryan

Great news Ryan,your efforts are much appreciated
The doctor is more than satisfied

[gerold]

Hi,
You can now download Fruit 2.2,2.2.1 and the strongest Beta 5 since November 2005

http://www.fruitchess.com/

Thanks Dr.Wael for the good news.

Thanks Ryan for your help.

A big thanks to Fabien for the strongest free chess
program to date.

Good luck,

Gerold.

[Dr.Wael Deeb]

Hi,
You can now download Fruit 2.2,2.2.1 and the strongest Beta 5 since November 2005

http://www.fruitchess.com/

Thanks Dr.Wael for the good news.

Thanks Ryan for your help.

A big thanks to Fabien for the strongest free chess
program to date.

Good luck,

Gerold.

You welcome Gerold
BTW,I have the feeling that releasing these free versions of Fruit means that Fabien's new chess engine will be a real monster

[Eelco de Groot]

The 051103 version sure has a lot of knobs to fiddle with. Does anyone know what they all mean? Pawn duos seem simple enough, but what about "Hisotry Reduction 1" and "History Reduction 2" and "Move Skip 2"? If someone know what they mean, please let us know.

Hello Mark, my guess these could have something to do with the intermediate tactics or intermediate quiescence layer (my wording) that Ryan Benitez was talking about in the Tournaments and Matches Forum.

Toga is a fine tuned version of the existing GPL Fruit with common well known enhancements. This is not a bad thing at all as it shows the advantages of the GPL. Fruit did not continue to follow the path of fine tuning and instead moved on to new/original ideas on how to search and evaluate. For example Fruit has an extra layer between search and qsearch for extending certain types of tactics. Although Fruit had some of the best beta testers around the number of changes made where never fine tuned to the point they could have been given more time. I hope that if Fruit gets released to the public people will find settings that they find to be improvements and share them with the community.

In that case probably there is more severe History Pruning in this layer, and the History Treshold 2 goes from 40 to 70. It could also mean conditions for History Pruning and Extended History Pruning however and not about this tactics layer before Q-Search, maybe Ryan could tell us more

LMR Move Number is probably equivalent to Move Skip 1 and Move Skip 2, this goes from 3 to 5 so actually a bit more cautious, in the second case late moves start with the 5th move, first with the third move. History PV Node is probably about doing history (or LMR) pruning in the main variation, the PV. Default it is switched off, probably best, switching it on is I think not better, in Glaurung I believe LMR is also switched off for the PV nodes. 3 and 5, the defaults, for the Move Skip numbers seem best.

Eelco

[tralala]

I try to clarify something on the extended history pruning. In fact it is similar to extended futility pruning where you reduce by 2 plies if the margin is bigger. The extended history pruning in Fruit reduces also by two plies if the history threshold is lower. To understand the values one must know that each move starts in Fruit with a history score of 100 and is reduced each time it gets some cutoff (beta, alpha I don't know) in short each case it is determined it is not the best move. With the current default values a line is reduced by 1 ply if the threshold goes below 70 and 2 plies if it goes below 40. History move skip means that no reduction takes place for the X best moves after the PV. The reduction also doesn't take place in PV Nodes (but there is an option to enable it - it results in much bigger search depth but overall no better play).
Well that is it I think, "Leaf Pruning" means pruning also takes place in QS iirc.

Pawn Duo is another interesting idea aimed to help with opening play. It gives a bonus on pawn duos on certain ranks and files. I think all options are selfexplanatory. It is meant to help pushing the central pawns forward in play without an opening book or for Chess960. However no strength increase could be proven so it is off by default.