Ultra

This thread was written before I properly understood how it worked.. so it's probably worth correcting this.
Hit Rate is effectively "damage efficency". The closer the number is to 99%, the more efficent the damage is dealt, relative to the attack multiplier.
A way of calculating it is Hit Rate * Attack Multiplier * Attack Power get a proper idea of damage being dealt. Also, a low hit rate has a higher degree of variation, which may or may not help the situation, which is why a hit rate of 99% is relatively stable and predictable in the damage that can be dealt.