Fruit with and without Futility and Delta pruning

[Volker Pittlik]

It has been written at CCC that there might be an increase in Fruit's playing strength by enabling Futility and Delta pruning. I tested that at a time control of 3 minutes plus 3 seconds increment and didn't find any noticable differences.

Futility and Delta Pruning off

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No. Name             Win Draw Loss Unf.  Score Games       %
------------------------------------------------------------
  1 Fruit_21         +37  =26  -37   *0   50.0   100   50.0%
  2 Shredder8+BT-GS  +37  =26  -37   *0   50.0   100   50.0%

Total Games:     100
White Wins:       50 (50.0%)
Black Wins:       24 (24.0%)
Draws:            26 (26.0%)
Unfinished:        0 (0.0%)

Futility and Delta Pruning on

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No. Name             Win Draw Loss Unf.  Score Games       %
------------------------------------------------------------
  1 Shredder8+BT-GS  +38  =28  -34   *0   52.0   100   52.0%
  2 Fruit_21         +34  =28  -38   *0   48.0   100   48.0%

Total Games:     100
White Wins:       38 (38.0%)
Black Wins:       34 (34.0%)
Draws:            28 (28.0%)
Unfinished:        0 (0.0%)

The games can be downloaded here:

http://volker-pittlik.name/winboard/tests/Fruit_21-Shredder-8_3_3_Futility_Delta_off.zip
http://volker-pittlik.name/winboard/tests/Fruit_21-Shredder-8_3_3_Futility_Delta_on.zip

Regards

Volker

[Norm Pollock]

I am able to turn on futility and delta pruning for fruit 2.1 through a parameter page using the fritz8 gui. But I have to do it each time I set up a "tournament" with fruit 2.1. It would be easier if I had a compiled version of fruit 2.1 that included futility and delta pruning already installed. Is there such a version available for download?

[Guenther Simon]

I am sure you can save as much personalities of Fruit 2.1
as you like, even under CB GUIs.

AFAIK you just have to save your changes under a different name.

Guenther

[Norm Pollock]

I am sure you can save as much personalities of Fruit 2.1
as you like, even under CB GUIs.

AFAIK you just have to save your changes under a different name.

Guenther

Hi,

I did save the personality in a "personality" file. But that personality file has to be manually re-loaded into the engine each time I insert the engine into a new "tournament". It's very easy to do, but it is also easy to forget to do it.

[Guenther Simon]

Hi,

I did save the personality in a "personality" file. But that personality file has to be manually re-loaded into the engine each time I insert the engine into a new "tournament". It's very easy to do, but it is also easy to forget to do it.

Hi Norm,

I have just tested it under a CB GUI I don't have your problems.
Before I have just created a new Fruit UCI engine with the name
and parameters I liked and if I load it in a tourney or for whatever
it is exactly the thing I have saved, nothing manually to do at all.
It seems you did _not_ create a new Fruit as I told you?

Guenther

[Norm Pollock]

Hi,

I did save the personality in a "personality" file. But that personality file has to be manually re-loaded into the engine each time I insert the engine into a new "tournament". It's very easy to do, but it is also easy to forget to do it.

Hi Norm,

I have just tested it under a CB GUI I don't have your problems.
Before I have just created a new Fruit UCI engine with the name
and parameters I liked and if I load it in a tourney or for whatever
it is exactly the thing I have saved, nothing manually to do at all.
It seems you did _not_ create a new Fruit as I told you?

Guenther

Hi Guenther,

Thanks Guenther, I did get it to work by doing: (1) changing parameters during installation of the engine a second time and (2) using a different engine name the second time. But it is not a "new Fruit UCI engine". It is another implementation of the same engine using the chosen parameters. CB uses the term "modified engine" for the new implementation.

I now have "Fruit 2.1" and the new implementation, which I named "Fruit 2.1 f-d", on the engine list. Even though they are both on the engine list, I cannot load both into the same tournament. Only one can be loaded per tournament. That is because "Fruit 2.1 f-d" is a "modification" of "Fruit 2.1" and not a separate engine.

Here is the "help" info from CB which may clarify this sticky topic:

"Modifying engines
Many UCI engines allow you to modify a number of search and evaluation parameters which influence the playing style of the engine. To change the parameters proceed as described above. In the Create UCI engine dialog click on the button Parameters.

Each UCI engine will display the parameters which can be changed, and which vary for different engines. If you change any of the parameters the input fields for "Name" and "Author" become active and can be modified, within the constraints described above.

After clicking "OK" the new engine is registered and will appear in the Fritz engine list, together with the other UCI and native Fritz engines.

Please note: modifying and storing an engine with a different name does not create a new copy of the engine on your hard disk. Only the modified parameters are stored under the new name and applied to the engine when this is started."

-Norm

[Guenther Simon]

Hi Guenther,

Thanks Guenther, I did get it to work by doing: (1) changing parameters during installation of the engine a second time and (2) using a different engine name the second time. But it is not a "new Fruit UCI engine". It is another implementation of the same engine using the chosen parameters. CB uses the term "modified engine" for the new implementation.

I now have "Fruit 2.1" and the new implementation, which I named "Fruit 2.1 f-d", on the engine list. Even though they are both on the engine list, I cannot load both into the same tournament. Only one can be loaded per tournament. That is because "Fruit 2.1 f-d" is a "modification" of "Fruit 2.1" and not a separate engine.

Hi Norm,

Fine that it finally works for you.
I just want to add though that you can of course create
a 'new' Fruit 2.1 too by just doubling your Fruit folder,
but then giving it a different name and the parameters
you like
This way you can play different Fruits against themselves
if you want.

Regards,
Guenther

[diepeveen]

There is a huge difference between blitz and slow level with respect to forward pruning, because at blitz the positional search depth isn't above 10 ply yet. Meanwhile still a lot of tactics get missed in blitz as it isn't at the required 12-14 plies you need to see there IMHO.

In my experience tactical deeper search in blitz works great.

Fruit's classical reductions in search ('history pruning') take care it gets tactical extremely weak, as it reduces *everything* after the first 3 moves tried.

If you combine that with other algorithms you must take a good look at 2 points :
a) the increase in search depth versus the risk in plies you might lose.

For example a very rude 'futility' last 3 plies that is going to miss a potential 3 ply search depth in a crucial line, at a search depth of 10 ply in blitz where you already lose up to a ply or 2 in advance to history pruning, that means that you see crucial lines to a search depth of 5 ply.

We didn't discuss nullmove even then.

White plays a move. Then comes history pruning, nullmove and futility. Effectively you just see 1 move deep and a qsearch at a search depth of 10 ply or so?

b) the positional effect versus the tactical effect

If you just see tactical moves the last 3 ply then that's going to hurt bad in slow time controls.

[Norm Pollock]

Hi Guenther,

Thanks Guenther, I did get it to work by doing: (1) changing parameters during installation of the engine a second time and (2) using a different engine name the second time. But it is not a "new Fruit UCI engine". It is another implementation of the same engine using the chosen parameters. CB uses the term "modified engine" for the new implementation.

I now have "Fruit 2.1" and the new implementation, which I named "Fruit 2.1 f-d", on the engine list. Even though they are both on the engine list, I cannot load both into the same tournament. Only one can be loaded per tournament. That is because "Fruit 2.1 f-d" is a "modification" of "Fruit 2.1" and not a separate engine.

Hi Norm,

Fine that it finally works for you.
I just want to add though that you can of course create
a 'new' Fruit 2.1 too by just doubling your Fruit folder,
but then giving it a different name and the parameters
you like
This way you can play different Fruits against themselves
if you want.

Regards,
Guenther

Got it to work this time. thanks.