There's no "hit rate" or "attack rolls" like D&D or anything like that, so you wont find anything like in RULEBOOK.pdf. TDB takes a very simple approach on melee, basically damage = (weapon damage - monster protection):
damage = power mod (i.e. if power = 24, power mod = 2) damage += rand(weapon damage min, weapon damage max damage -= (monster protection * 0.8)
if you knight can't hit much it could either be 1) his power mod is low / negative 2) his weapon damage is low
Check more on RULEBOOK.pdf under:
- "3.3. Initial computed values"
- "9.4.2. Damage by Melee weapons"