UO Second Age

Can anyone explain to me what the difference is between 50 & 100 blacksmith when trying to repair a weapon?

If you successfully repair an item, does skill determine the effectiveness of the repair, or is repair a full repair regardless of skill.

I believe the Max hit points of the item decreases on each repair. The higher your smithing skill the less this decreases each time. Also smithing skill is your chance to not-break the weapon.

At least that's how I understand it.