How Fast is Billy Hamilton?

As fast as he appears to be:

MLB Advanced Media, the tech outfit owned by baseball's 30 clubs, is rolling out a new tracking technology that yields insights about the entire field of play -- not just the pitch or the hit. Through a combination of cameras, radar, and proprietary software, the new system provides data on a base runner's jump and speed and the angle of his path while trying to, say, steal second base. It can also capture information on the catcher, fielders, and more.
Using this still-unnamed technology, MLBAM (known internally as BAM) crunched some numbers exclusively for Fortune that suggest that the single fastest guy in baseball is probably Cincinnati Reds rookie Billy Hamilton: In a September game against the Milwaukee Brewers, Hamilton, who was called up from the minors last season just for the playoffs, successfully stole second base in the eighth inning. The new system revealed that he had a 10.83-foot lead, clocked a jump of 0.49 seconds, and hit a top speed of 21.51 mph (rather insane), and that the entire steal occurred in only 3.08 seconds. Meanwhile, it took the Brewers' catcher 0.667 seconds to get the ball out of his glove and release his throw to second; his throw traveled at 78.81 mph -- fast, but not fast enough to tag Hamilton out.

If you want to see how fast he is, check out this clip.