Here is a brainfart I had while sitting in front of the teevee, taking a moment or three from my other duties:
Take this number: number of strikes thrown in a complete game, which is important, that one pitcher throws a complete game. I personally like any perfect game, but it takes some off the prestige when the bullpen steps in to complete the gem after the starting chunker poops out.
Divide by whatever pitcher's earned run average.
(complete game called-strike count)/ERA
The resulting figure may then need have it's decimal adjusted to resemble a normal percentage, but I feel the result is something close.
Don't you just love it when I have a spare moment to think? Rhetorical question of course. As the old proverb states: Don't ask a question when you know you will not like the answer.