The most two important statistics for a guard are assist to turnover ratio and points per game. Kobe has Mr. Pierce in spades in these categories, and he's been consistently better for quite some time now. Here's their assist to turnover ratios on a span of careers (I've truncated Kobe's first two years to compensate for the fact that he was good enough to go straight to the pros):

And here's points per game:
Aside from one (oddball) year in each category, Kobe comes out victorious. I got the data from their Yahoo player profiles (here and here). And since Kobe is on the Lakers, the Lakers win.Unfortunately, that means that the Celtics lose. Sorry guys, you gave it your all, but in the end, Kobe came out on top. Better luck next year.