from Amazon
Wednesday, September 30, 2009
HR presentation
Ah, this I like:
The bottom line is the horizontal location of the pitch (from the catcher’s view point, so a lefty hitter is on the right side, and the +1 means a pitch inside), and the top line is the angle of the HR (-45 is 3B and +45 is 1B). He also color-coded the lines by pitch type (legend not provided). So, for example, we see that the red-pitch (whichever one that is, let’s presume it’s a changeup) was thrown inside 4 times for a HR, and never outside.
It takes a little getting used to. If you look at the first red-line, you see that the horizontal location was near the middle of the plate, and the spray angle was around 30 degrees. The last red-line was thrown way inside, and had a spray angle of 45 degrees. But, the visual line you see is actually a sharper “angle” for the first line. So, that part is confusing. The visual angle you see of the line itself is meaningless: what we care about are the two endpoints that link the line.