Author Archives: admin

chess4j 3.5 is released

I’m releasing version 3.5 of my Java based chess engine, chess4j. The only changes since 3.4 are some bugfixes to the ponder search and changes in some logging levels. As always the source code is available on the project website … Continue reading

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Prophet3 20180811 is released

It’s been about a year since the last release of Prophet3, which was version 20170909. The main changes since then are the addition of a pawn hash table, improved Winboard compatibility, and a ponder search (*). I also added a … Continue reading

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chess4j 3.4 is released

chess4j 3.4 is officially released. The main changes in this release are the hashing related changes that I discussed some time back in this post. Other than that, there are many smaller changes, many of which I’m sure I’ve lost … Continue reading

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Hashing in chess4j

Hashing is an area I’ve meant to revisit in chess4j since it was originally implemented, for a couple of reasons. (1) The hash entries consume too much space, limiting the number of entries the hash table can store, and (2) … Continue reading

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Another round of sparring partners for Prophet3

Back in early March I added aspiration windows to Prophet with a window of 1/3 pawn, as well as some futility pruning and delta pruning. My schedule hasn’t allowed me to do a lot of work on the code since … Continue reading

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chess4j 3.2 is released and it’s magic!

I just released chess4j 3.2. This release is purely about optimizing for speed. That is, there are no changes to the search or evaluation terms. chess4j is now a bitboard engine, and uses magic bitboards for move generation. Simply by … Continue reading

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Prophet’s sparring partners

Several months ago I decided to get a little more rigorous about how I test changes to Prophet. With previous versions of Prophet, I would make a change, run some test suites consisting of a few hundred or a thousand … Continue reading

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chess4j 3.1 is released

I just released version 3.1 of chess4j, my Java based chess engine. This version is about 100 elo stronger than 3.0. The key differences are: The Groovy language is no longer used. Groovy is a fine language for some purposes. … Continue reading

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Prophet is back

After a VERY long absence from server play, the rewrite of my chess engine Prophet is finally far enough along to play some games online. The engine itself has been capable of play for a little while now, but I’ve … Continue reading

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chess4j 3.0 is released!

After a long period of inactivity I’m happy to announce the release of version 3.0 of my Java chess program, chess4j. This version is a good bit stronger than the previous version, though still not as strong as my C/C++ … Continue reading

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