- The depth of the entry must be at least the root depth of the last search
- The last search must have taken more than the "average" time taken for a search
As far as I can tell, this isn't present in any of the top open source engines, but, based on testing, it seems to significantly improve playing strength at short time controls, as it leaves time for other moves to be searched more deeply.
Has anyone else considered/tried this? Are there any caveats I should be aware of?