Closer's don't usually face the opposing pitcher, so I don't know why the numbers wouldn't translate. The hitting talent gap between the AL and NL is not that great. The predominant reason for more runs in the AL is the DH. The NL has just as many young rising stars, maybe more than the AL. Let's not forget that the WS champion barely played .500 ball and they kicked the crap out of the AL Champ. The AL is not that much superior to the NL. It has a different style of play that produces more runs. That's about it.