Houdini 2 - The Chess Engine
Improved Analysis support:
Save Hash to File, Load Hash from File, Never Clear Hash
The complete hash table can be saved to a disk file and reloaded later for continuing the analysis.
Houdini 2 makes better use of the data in the hash table to restart instantly the analysis at the point where it was previously interrupted.
By saving the hash table in a disk file you can interrupt the analysis anytime. At a later date you can reload the hash table file in memory to continue the analysis as if no interruption had happened.
The new "Never Clear Hash" option will keep the hash data in memory even when the position changes or when starting a new game.
The "Position Learning" mode will automatically save analysis results in a learning database that will be reused in future analysis. This is a more convenient, but less powerful method of using previous analysis results than the manual Save Hash/Load Hash operations of the previous point.
Strength Limit feature
Houdini 2 can limit its skill level from 0 (beginner) to 100 (full strength).
The strength is limited through a combination of techniques: limiting the number of positions searched, purposely picking a non-optimal move, and ignoring table bases.
Up to what skill level can you beat Houdini?
Chess960 (Fischer Random Chess) Support
Houdini 2 supports Chess960 a.k.a. Fischer Random Chess games.
To speed up solving deep mates, you can fix a limit on the search depth during the mate search.
Improved evaluation and search make Houdini 2 Standard about 25 Elo stronger than its predecessor Houdini 1.5a. On high-end hardware Houdini 2 Pro with its additional NUMA-related speed improvements is about 40 Elo stronger than Houdini 1.5ab-16.