http://forums.worldofwarcraft.com/threa ... 2116&sid=1

About 1/2 way down the page is the info u need.

5/5 shadow focus only 76 hit ? what have they been drinking ???

m8 i hardly ever get a resist or no hit and I'e been based on #'s like that for ages.

Yep, if you have 5 points in Shadow Focus, +76 +spell hit is indeed right.

At level 70 you have on average an 84% chance to hit will spells, you thus need an extra 16% +spell hit to hit the normal cap (cap is 99% as there is always 1% resist chance on any mob or boss), which usually equates to 202/203 +spell hit. (15 +hit = 1% chance)

If you have Shadow Focus (or Suppression if you are a Warlock), you already have 10% of that, so you only need 6% extra, and thus need 76 +spell hit to hit the 16% cap.

Imho, it makes a *huge* difference being at the cap, and for locks at least, would be a minimum requirement for raiding.