May 17, 2007

[New Version] v0.33 - Pawn and eval hash

  • Eval hash added
  • Pawn hash added
  • The zobrist keys are now pseudorandom, meaning they stay the same when restarting the application
  • Pawn zobrist key added to the Board class
  • Pawn eval divided between structure and passed pawns to fit with the pawn hash
  • Switched name between 'depth' and 'ply' in the search, depth is the number of plies left to search ply is the number of plies deep the search currently is
  • Fractional plies added
  • Matethreat extension and pawn to 7th rank extension added
  • It is now possible to change the transposition table size in the mediocre.ini file
Note: I am not so sure about strength difference between v0.32 and v0.33, the new version runs faster for sure but there might be some bug somewhere that I have no yet found. Anyway I thought I should release this and see how it works for other people.

I made new addition to the readme.txt about setting the hash table size, here it is so you do not miss it. :)
Mediocre now comes with mediocre.ini in which you can set the size of the hash tables, and decide wether the own opening book should be used.

Since Mediocre is a Java engine it gets 64mb RAM allocated by default. In the .bat file I have now added "-Xmx1024M" which allocates 1024mb RAM instead. This is NOT the size of the hash tables or how much RAM Mediocre will use, it is merely the maximum amount the application CAN use.

If you set the size of the hash table to anything larger than the allocated memory Mediocre will not run. If you want more RAM to be allocated simply increase the number in the -Xmx1024M (e.g. -Xmx2048M). Again this is not how much the application will use, but how much it can use. Decreasing the number will have no other effect than not making Mediocre start if hash table size is set to anything larger.
Have fun playing around with it. :)

Edit: Fixed the version number in the application. Thanks Jim for noticing.



Fritz said...

The change to deterministic play is a good decision. Both updates 0.32 and 0.33 increase the strength of Mediocre a lot. Congratulations to your success! What rank do TBs have on your priority list?

Jonatan Pettersson said...

Thank you. :)

Table bases is quite low on my priority list. They will come eventually but to me they're not that interesting, more of a technical feature than actual engine development.