I agree with Princess L's (crossed-out?) comment. I mean, to degree it's ok to say "shit, the Bench racks are in use, i'll do DBs" or "damn, my ass is sore, i'll pre-exhaust my quads". But to say "hmm, today i'll do quads" or something to that effect is a bit, for lack of a better word, retarded. There's nothing wrong with doctoring your workout a bit, but doctoring your split constantly is a recipe for disaster. Or mediocrity.