Gull engine : Which depth value to set 6 difficulty levels? 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?
You may find this post by the developers of the website https://lichess.org/ helpful.

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).