We are installing the Gull engine for some chess enthusiasts in an organization. We would like to set 6 difficulty levels from beginner to master using depth. Is there someone who can advice us about which values are the most accurate and progressive for each level?
Although they use Stockfish as the engine, they set the search depths as such (note that they have eight levels of play):
- AI level 1: skill 3/20, depth 1, 50ms
- AI level 2: skill 6/20, depth 2, 100ms
- AI level 3: skill 9/20, depth 3, 150ms
- AI level 4: skill 11/20, depth 4, 200ms
- AI level 5: skill 14/20, depth 6, 250ms
- AI level 6: skill 17/20, depth 8, 300ms
- AI level 7: skill 20/20, depth 10, 350ms
- AI level 8: skill 20/20, depth 12, 400ms
I have personally played and seen others play against the varying levels. Level 1 is almost joke worthy--the computer may move his queen completely into danger, completely miss checkmates, etc.
On the other hand, level eight is crushing; beating it requires repeated practice over the same line (at least, that is the only way I've seen people beat it).