Nathan: Hunter Pence’s triple-double in the NLCS

From SABR member Alan Nathan at The Physics of Baseball on October 23, 2012:

During Game 7 of the 2012 NLCS, October 22, 2012, Hunter Pence came to bat for the Giants with the bases loaded, nobody out, in the bottom of the third. He hit a grounder to the left side, normally a tailor-made double play. Now take a look at the two video clips shown below. In the first clip, we see a wide shot showing that the Cards shortstop Pete Kozma initially moved to his right, then recovered to move to his left but just out of reach of the ball. In the second clip, we see a high-speed video of the ball-bat impact, which is one of the most remarkable events I have ever seen. With the initial impact near the center of the bat, the bat breaks and the ball comes slowly off the bat. Meanwhile, the bat continues to rotate, catches up and impacts the ball a second and third time before the ball finally exits to the playing field with lots of sidespin on it. It is the sidespin that leads to the slicing action in the trajectory that takes it just out of the reach of Kozma. As you might imagine, there is a lot of physics contained in this play, and I want to explore some of it in this article.

So, let’s try to pick apart what happened, highlighing what I consider the interesting physics. The ball hits initially off a region close to the center of the bat, where the vibrational amplitude for the lowest-frequency (“fundamental”) vibrational mode is large. The resulting large-amplitude vibration breaks the bat.

Read the full article here: http://webusers.npl.illinois.edu/~a-nathan/pob/PenceTripleDouble.html



Originally published: October 23, 2012. Last Updated: October 23, 2012.

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