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 depth preferred hash table, and tried using it in combination with an “always replace” table, but surprisingly that seemed to be slightly weaker. I plan to revisit this idea – it seems it should work.
* – A ponder search means Prophet will take advantage of the time the opponent is “on move.” Instead of idling, it assumes the opponent will make the next move in the principal continuation evaluated from the last search. If the opponent doesn’t make that move, then nothing is lost, we just start the search over. If, however, the opponent does make the predicted move, then we are already that much closer to having a response ready. In some cases, we may play an instant response. This can be a huge time saver, allowing us to allocate slightly more time-per-move to the engine.
This version isn’t much stronger without pondering, but with pondering on it gains about 40 elo vs my standard set of opponents. Here are the current test results (without pondering):
| Rank | Name | Elo | games | score | oppo. | draws |
|---|---|---|---|---|---|---|
| 1 | plisk 0.2.7d | 101 | 26870 | 62% | 15 | 19% |
| 2 | tjchess 1.3 | 97 | 28184 | 62% | 15 | 21% |
| 3 | jazz | 71 | 31167 | 59% | 6 | 19% |
| 4 | myrddin | 50 | 34344 | 58% | -8 | 19% |
| 7 | prophet3-20180811 | 1 | 25776 | 46% | 29 | 24% |
| 5 | Horizon 4.4 | -3 | 34342 | 50% | -4 | 17% |
| 6 | tcb 0052 | -8 | 34342 | 49% | -3 | 19% |
| 8 | jumbo 0.4.17 | -15 | 34502 | 48% | -3 | 20% |
| 9 | madeleine 02 | -59 | 34502 | 41% | 1 | 19% |
| 10 | Beowulf 2.4a | -96 | 22380 | 39% | -21 | 18% |
| 11 | prophet 2.0 e1 | -106 | 19180 | 40% | -35 | 18% |
| 12 | matheus 2.3 | -114 | 19180 | 39% | -34 | 17% |
Binaries can be downloaded from Prophet’s home page. Source code is available on Prophet’s Github repo. Enjoy!