On September 8, Mike Aviles had a season line of .289/.317/.350. The batting average looked ok on the TV screen each night, but the lack of any complementary contributions made his overall offensive profile right in the Betancourt/Bloomquist range.
Since then, Aviles has hit .397/.420/.705 in 81 PAs. Thanks to his surge, Aviles has raised his season line to a more respectable .310/.338/.420. He's needed to hit .400 for three weeks to get there, but Aviles will now likely end the season with an acceptable OBP, which we should remember is by far and away the most important offensive stat.
So what, if anything, does this mean for Aviles?
Well, for him personally, it probably means that he's earned a little more career certainty. Aviles has always been, so to speak, on the outside looking in, and he'll now finish with a superficially solid 2010 line to compliment his 2008. Absent this hot streak, what was Aviles really? He was a low-scouting-pedigree guy, with one good year, and bad injury history. Now, the narrative changes. He's hit well at the Major League level, he's comeback through a serious injury, and he's worked to re-establish himself.
In terms of thinking about Aviles's career more broadly, it is less obvious what his September "means". For me, it re-establishes that he has a reasonable amount of ability to hit for a very high average for long stretches. He's not patient enough to ever fully profile as a complete offensive player, but for a middle infielder, he can be worth a roster spot.
There's an old baseball belief that September numbers shouldn't matter because of September call-ups. I think that's an over-simplification: it isn't like every non-contending team has emptied their roster of any frontline talent. Moreover, in some cases, the September callups are actually improvements, and they allow managers to use more pitchers and in some cases fresher pitchers. Finally, there's the problem of quantifying the extent of the supposed weakening? Is the pitching Aviles has faced 5% worse? 10%?
For me, the bigger issue is simply sample size. I don't worry about a player being hot in September, so much as I worry about a player merely having a hot month. Any month. We shouldn't get too excited about Aviles hitting so well this month, by any means. He hasn't established a new performance level, he's just hot.
Then again, there's a certain skill to being a batting average driven player. Alex Gordon, for example, is probably not capable of hitting .400 for three weeks. It's just not part of his profile. With Aviles, there's some reason to believe that, from time to time, he will hit .350 or higher for an extended stretch. Sure, he won't be walking any, and the power isn't going to be much, but he'll still drive the offense... for a time.