Justin Upton is off to a hot start; he's probably the hottest player in baseball right now no matter how you look at it. Whether you take a traditional look (10 home runs in 19 games) or a more advanced one (1.4 WAR, Fangraphs), he more or less leads the league.
But, as Hardball Talk's Matthew Pouliot writes, he still is missing something from his game: RBIs. Upton has only 14 of them, despite his 10 home runs. That seems incredible-is Justin Upton un-clutch?
That's a ridiculous thought. Let's look at Thursday's box score, the first game of a double header and the game where Upton hit number 10 out. Upton batted third-that's unsurprising. Ahead of him in the lineup? Andrelton Simmons and Justin's older brother B.J. They have on-base percentages of .292 and .247 so far, respectively. That won't last, but for the time being, the three batters ahead of Justin in the order are a pitcher and two guys with OBPs below .300.
People have to be on base for you to drive them in.
EDIT: After game two, those figures are now 11 home runs, 1.9 WAR, and 16 RBIs.