Rag, MrFuji is explaining the maths accounting for expected hit rates - they need to be considered when dealing with things that affect your chance to hit, after all. For example, a hit with an average damage of 20, and a 50% expected hit rate has an expected average damage of 10; that is, over 100 'swings', you would expect to do roughly 1000 damage total, by the averages.
I see ... thats why i asked, thank you.