by Bob Bentz
Aroldis Chapman hit 103 in his debut last week against the Brewers and some guns had him as high as 105.
Chapman pitched in two games and two innings versus the Milwaukee Brewers last week. He threw just 19 pitches in retiring all six Brewers that he faced. Of the 19 pitches that he threw, 10 topped the 100 MPH mark! His fastest pitch was clocked at 103.9.
According to Baseball Almanac, the fastest recorded pitch in MLB history is 104.8 by Joel Zumaya of the Tigers in October, 2006. The only other pitcher in the radar gun era to hit 103 was Mark Wohlers of the Braves who hit it during Spring Training 1995.`
Robert Adair, author of The Physics of Baseball and a professor from Yale, said that a pitcher’s fastball takes about 0.45 seconds to arrive in the catcher’s mitt. But, that’s just an ordinary fastball; not a Chapman fastball. According to retired Penn physics professor Howard Brody, a ball thrown at 103 MPH takes just 0.396 seconds to arrive at home plate.
Brody, however, didn’t take into consideration that Chapman was striding toward home plate when he throws. Hence, the distance the ball needs to travel is less than the 60 feet 6 inches from the rubber to the plate.
A pitcher’s stride length is normally 80 to 90% of his height. Therefore, a 6′ 4″ pitcher like Chapman will have a further 5.1 feet advantage at his release point. Now, I’ve gone to Yale and Penn also in my lifetime (to buy a pizza). But, this says to me that the real reaction time for a batter is 0.362 on a Chapman fastball. Now, add to the fact that a batter must hit the ball out in front of the plate, not on it. Oh heck, this is getting way too complicated for me now so I’ll stick with the 0.362 reaction time on a Chapman fastball.
eFastball reports the typical pitch reaction time for big fields as .424 at 90 MPH, .480 at 80 MPH, and .553 at 70 MPH. Most high school pitchers will be in the 75 – 80 MPH range. At the Little League level, a 60 MPH fastball that is typical at the recreational level has a .478 reaction time and a Williamsport level 70 MPH fastball has a .407 reaction time. Makes you wonder how any Little Leaguer ever gets a hit?
I’ve stood in the batters box against Major Leaguers like Mitch Williams just two years after retiring so I know what a 90 MPH fastball looks like so I’ll just have to imagine what Chapman’s 103.9 looks like.