Recently while gazing self-pleasuringly at the Pitch Type leaderboards, I had a spasm of analytical curiosity. (Don’t worry, these don’t last long.) Who sees the fastest fastballs? I asked myself. The simple answer is just a sort away: Jose Bautista, with an FBv of 92.5. There are no fewer than four Yankees in the top eight, led by Alex Rodriguez, who has faced heaters this year averaging 92.4 mph. But this isn’t so remarkable, I realized, as it might look at first. After all, A-Rod & Co. (as well as Joey Bats) happen to inhabit the hardest-throwing division in baseball, with power pitchers like David Price, Matt Moore, and Jon Lester padding those averages. What would this leaderboard look like if we somehow accounted for that?

Because I had some time on my hands, and because I am desperate to reclaim some shred of the dignity I’ve lost over several months of NotGraphs posts, I invented a new metric called Expected Fastball Velocity, or xFBv. For each hitter, I looked at every plate appearance this year and averaged the FBv of each pitcher faced. So, A-Rod’s xFBv is 91.7: if every hurler A-Rod has faced in 2012 had thrown him his average fastball, A-Rod’s overall average fastball faced would be approximately 91.7 mph. This is interesting because, as stated above, A-Rod’s actual FBv is 92.4. Pitchers are throwing to him, on average, a full 0.7 mph faster than they are throwing to hitters in general. This 0.7 number we can call FBv+, which sounds almost obscenely saber-y, I must say. Now, 0.7 seems pretty darn high. Does anyone have a higher FBv+? Why, they do!

What a terribly interesting list! For comparison, here are the bottom twenty:

My! Again, how terribly, terribly interesting! Now, after much perusal and beard-stroking and a few fumble-fingered Excel maneuvers, I managed to determine the following.

Batters with higher FBv+’s tend to be one of the following:

– Better hitters (e.g. Bautista, Cabrera, Pujols)

– Larger individuals (e.g. Goldschmidt, Heyward, Butler)

– Freer swingers (e.g. Soriano, Francoeur, Pence)

…whereas the classic low-FBv+ guy is a pint-sized, weak contact hitter like, say, Jemile Weeks. But this can’t be the whole story. Why does Dan Uggla lap the field so impressively? Why are there three Nats in the top five? Do pitchers overcompensate in the presence of the flamethrowing Washington staff? Is the presence on that leaderboard of such controversial names as A.J. Pierzynski, Alex Rodriguez, Hanley Ramirez, Starlin Castro, and Bryce Harper just a coincidence? Do pitchers throw harder to batters they hate? Could we use these numbers to develop a Hate Index?? And if so, why in the world is Melky Cabrera so low?? Discuss, readers! Discuss!

And if you need a chaser after all that Real Analysis, I suggest a workout with Dan.