Author Archives: admin

Prophet4 rewrite status 9/24/19

Evaluator complete. This is a verbatim “migration” of Prophet3’s evaluator. It was a little painful really, because the evaluation routines are clearly a major weakness in the program, but I think it’s important to port everything over and run some … Continue reading

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Prophet4 rewrite status 8/30/19

The protocol handler is complete. Enough of the XBoard protocol has been implemented to play a complete game. Move selection is completely random. A 20,000 game match was run between identical copies of the program (which didn’t take long since … Continue reading

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Prophet4

I’ve decided to start fresh, and completely rewrite Prophet from the ground up for the third time. The first iteration of Prophet was written around 2000. Prophet2 was started in 2007. Prophet3 was started in 2011 (see Shall we play … Continue reading

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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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