Chess engine: Eubos 2.26 (java engine)

- November 28, 2023

Eubos - a basic Java chess engine, written for kicks. Uses jcpi for the UCI protocol parts. Kind of weak, doesn't evaluate for king safety, for example. Now uses transpostion hashing, but because it runs in the Java VM on a bog standard PC, doesn't search very deeply (around 100K Nodes/s, though this is actually quite hard to evaluate due to the hashing).

Author: Chris Bolt Rating CEDR=2478

v.2.26

This release works around an issue whereby the move returned in the UCI best move command could be different than the computed principal variation. That is always bad, sometimes awfully bad. The defect seems to be most prevalent at longer time controls, it is possible its impact is fairly neglible in bullet and faster blitz time controls.

To install Eubos as an engine in Arena:
1. Select Engines > Install New Engine
2. In the file browser dialog that appears, change the drop down to *.bat
3. Navigate to the Eubos binary location, select the Eubos.bat
4. Select UCI protocol to communicate with Eubos
5. That's it!

Eubos - Rating CEDR progres

Pl	Engine	Rating	Score	Games	%
1403	Eubos 2.21	2478.8	79.00	269	29.37
1406	Eubos 2.20	2473.7	4.00	38	10.53
1413	Eubos 2.23	2459.1	69.00	327	21.10
1451	Eubos 2.22	2403.5	41.50	138	30.07
1458	Eubos 2.16	2391.7	34.00	100	34.00
1466	Eubos 2.14	2386.2	17.50	82	21.34
1485	Eubos 2.15	2360.0	49.50	154	32.14
1503	Eubos 2.17	2319.9	20.50	140	14.64
1551	Eubos 2.19	2239.5	6.00	28	21.43
1562	Eubos 2.12	2225.2	13.00	83	15.66
1586	Eubos 2.10	2168.1	6.00	30	20.00
1717	Eubos 2.3	1848.3	5.50	62	8.87
1750	Eubos 1.0.8	1681.9	9.00	42	21.43