I don't know, ERA is a pretty useless stat. Santana gets shelled one game, Schilling pitches a shutout and their stats are close to even again. I still think those stats are pretty close and as I said right now I'd give it to Santana and I would expect Santana to close the year out well and win it, but its hardly a lock yet.
Its not likely to happen but what if Santana pitches 2 IP, 7 ER his next start. Suddenly his ERA jumps to 2.92. Schilling pitches a 9 IP shutout. His ERA is down to 3.16. One game, albeit an unlikely game puts their ERA pretty darn close to each other. I don't think his lead is so huge that you can call it a *lock* yet was my original point. Santana has a lead but its not locked up.