Poisonous Skitterer Kill

Instants are counted from their success event and hard casts from their cast start, because the 3.3.5a client only ever logs one or the other. A hard cast interrupted before it landed still counts — nothing in the log distinguishes it. A few spells, Arcane Missiles among them, this client announces not at all: those are counted from their own ticks instead, one cast per burst of them.

Burnrage Frost 4 casts

Spell	Casts	Per min
Arcane Explosion	2	24.5
Blizzard	1	12.2
Cone of Cold	1	12.2