Last night, rookie Detroit Pistons center Andre Drummond air-balled two free throws in a row.

Drummond is now shooting 35.2% from the line this year. That's the third-worst free throwing shooting season in the history of the NBA (among players with more than 100 attempts).

Here's the video (more below):

So how exactly is he so bad?

Some of the reason is size.

Kevin Pelton of Basketball Prospectus ran the data and concluded that, generally, height hurts free throwing shooting. He concluded, "For each inch taller, players tend to shoot 1.2 percent worse from the line."

Pelton noted that part of the reason big guys shoot worse is that there are so few of them. He writes:

"As was noted at Sloan, part of the reason big men tend to be worse as shooters is that the smaller pool of extremely tall players and limited need for them to shoot well allows teams to tolerate a lack of skill they would not accept at other positions."

In short, there's no big incentive for big men to learn how to shoot.

There's also a "big hands" problem at work, according to former ESPN writer John Hollinger. He said having big hands and long arms really impairs a player's ability to shoot:

"Besides height, the physical trait that marks most NBA basketball players is that they have unusually long arms and, in many cases, enormous hands. This is tremendously useful on a basketball court in general, but at the free throw line it's an active impediment. It's very hard for a long-armed player to have a compact, quick shot release -- instead, for many, they can scarcely get out of their arms' way and end up with a slower, looping release."

Drummond is 6'10", and he has 9.5" hands, the second-biggest in the 2012 NBA Draft (seriously, look it up).

Obviously not all big men shoot as bad as Drummond. But he does have a lot of physical factors working against him that contribute to his historically awful shooting.