level difference	hit cap % PVE	hit cap % PVP	hit rating PVE (lvl 80)
-4	0%	0%	0
-3	1%	1%	26.23199272
-2	2%	2%	52.46398544
-1	3%	3%	78.69597816
0	4%	4%	104.92797088
+1	5%	5%	131.1599636
+2	6%	6%	157.39195632
+3 (skull level boss)	17%	13%	445.94387624
+4	28%	20%	734.49579616
+5	39%	27%	1023.04771608

Rating	Level 60	Level 70	Level 80
Spell Hit	8	12.61538506	26.23199272
Spell Critical Strike	14	22.07692337	45.90598679
Spell Haste	10	15.76923275	32.78998947

%	Spell Hit Rating (lvl 80)	Typical case	draenai %	Spell Hit with draenai
17%	445.94387624	hit cap	16%	419.71188352
14%	367.24789808	EP or (no EP + misery/improved faerie fire)	13%	341.01590536
11%	288.55191992	EP + misery/improved faerie fire	10%	262.3199272
8%	209.85594176	EP+AF (57/3/11) + misery/improved faerie fire	7%	183.62394904
1%	26.23199272

Spell	Talents / metagem	Crit multiplier (no T7)	Crit multiplier (with 4pcT7)	Note
arcane spell	(no CSD)	150%	152.5%
arcane spell	CSD	154.5%	157.225%
arcane spell	spell power	175%	177.5%
arcane spell	spell power + CSD	181.75%	184.475%
frost spell	ice shards	200%	202.5%
frost spell	ice shards + CSD	209%	211.725%
Fireball/Frostfire bolt	ignite	210%	213.5%
Fireball/Frostfire bolt	ignite + CSD	216.3%	220.115%
Fireball/Frostfire bolt	ignite + burnout	245%	248.5%
Fireball/Frostfire bolt	ignite + burnout + CSD	254.45%	258.265%
Frostfire bolt	ignite + burnout + ice shards	315%	318.5%
Frostfire bolt	ignite + burnout + ice shards + CSD	330.75%	334.565%
--
am (glyphed)	spell power	187.5%	190%
am (glyphed)	spell power + CSD	195.375%	198.1%
blizzard	spell power + 2/3 ice shards	208%	210.5%	57/3/11
blizzard	spell power + 2/3 ice shards + CSD	217.72%	220.445%	57/3/11
blizzard	spell power + 3/3 ice shards	225%	227.5%	56/3/12
blizzard	spell power + 3/3 ice shards + CSD	236.25%	238.975%	56/3/12

(crit multiplier formula listed in the formula section)