Jason Bartlett's BABIP is .384. His BABIP over the last three season are .354, .301, and .336. He is 29-years-old (30 in two months) and stands 6'. We have nearly 1,500 plate appearances to go off from the past three years, but people are more than content to look at this year and say, "Look, this is Bartlett. He'll be fine!" His regular season stats are going to be inflated, but don't fall into the trap of assuming a .393 wOBA is what we should expect moving forward.
Entering yesterday he had played in 84 games. If you simply cut that into half you get a .996 OPS in the first 42 and a .768 OPS in the second. He's not "going to regress soon", no, he's already regressing. Nobody talked about it, but over his last 99 plate appearances his OPS was .694. Look at his monthly splits by OPS and BABIP:
August is far too small of a sample size to use, but is it really a coincidence that Bartlett's OPS went down the drains when his BABIP did? Mind you, a .305 BABIP is actually above league average but still below what Bartlett has recently shown he's capable of. Look at his walk rates:
With his best walk rate and an okay BABIP, Bartlett managed a .692 OPS. In future weeks you should expect his BABIP to expand and his walk rate to decline. Bartlett went back to being what he is: a slap hitting shortstop who hits liners and not home runs. He had a very nice game today and just so happened to hit leadoff, that's it. He's not going to hit for a .900 OPS moving forward. B.J. Upton probably won't either - and as an aside I have legitimate fears that his shoulder may be hurt again based on his July, his BABIP was decent but he hit for absolutely zero power, that's not good.
If you want to make a change at the leadoff spot, fine, but Jason Bartlett isn't the full-time answer.
Before someone takes this as me arguing for Upton remaining leading off let me state it clearly: I am not arguing that.