'''-Minimum Skill''': There appears to be a minimum skill tick size that is set by your current skill and possilby some other factors like how far above the critters skill you skill is. You get the minimum when your skill is higher than the soul crystal creatures skill. Effective ql, critter idenity, and rare+ seem to have little or no affect on the minimum skill gained, especially if you skill is much higher than the critters. Rare+ may give higher skill, but not if its a minimum gain.
When you get a minimum gain the event tab says: "[01:30:04] Your knowledge of Body control already surpasses that of the former rooster, but you still manage to learn something."
Dirk Minimum Strength Data: