Why do pitchers throw overhand in baseball but underhand in softball?
Dear Straight Dope:
My barber asked me this: why is a softball pitched underhand and a baseball overhand? I know it's in the rules, but why?
Brace yourself, Zach: there's no rule that requires a baseball pitcher to deliver the ball overhand. There have been several sidearm pitchers, and a couple of submarine (underhand) throwers, in the major leagues, with varying degrees of success. Juan Marichal was known for throwing overhand, underhand, and sidearm, and had six 20-win seasons and a career ERA of 2.89. Dan Quisenberry was a sidearmer whose delivery became more submarine later in his career, after working with Pirates submariner Kent Tekulve. Quiz finished his career with 244 saves out of 674 relief appearances, and an ERA of 2.55. In 1998, Rolando Arrojo pitched his rookie season for the Devil Rays (14-12 in 1998, with a 3.56 ERA), although, like Marichal, he varies his delivery among overhand, sidearm, and submarine, giving the illusion that he has a dozen or so pitches in his bag.
So, why don't more pitchers throw this way? Partly because it's simply unconventional. If your parents, little league, high school, or college coaches don't know about the mechanics of underhand pitching, you'll likely be discouraged by them, or by the batters who hit you, or who you hit. Also, those mechanics ARE different. So much about baseball control and speed comes from an overhand motion, including the wind-up, the whiplike explosion off the mound, and the follow-through. While it's not impossible to pitch with major league speed and precision throwing underhand, I venture to say it's more difficult.
Then, why must softball pitchers throw underhand? Because historically softball pitchers weren't supposed to throw fast. Softball was created as a way for ball players to play indoors in the winter, and was necessarily slower paced than baseball, with more fielders, a smaller field, and a bigger ball. Being indoors, there was no pitching mound, and throwing from this position was considered potentially harmful to a pitcher's mechanics, so often a coach or manager would simply toss the ball, underhanded, to put it in play for practice purposes.
Competitive softball started to take off in the 1930's. In the '50's, in order to accommodate less skilled players, some more recreational leagues restricted the pitch to underhand throwing, no wind-up, a reasonable speed, with a perceptible arc. No pitcher's mound is used in softball, even though the game is played outdoors now, because it would give the pitcher a mechanical advantage. In fast-pitch, of course, softball was more competitive, without restrictions on speed, arc, or wind-up (well, sometimes; some leagues restrict certain wind-ups to this day), but the legal throwing motion was still limited to underhand.
There are some great fast-pitch softball pitchers out there, of course. But you'll notice that the method of throwing a great underhand softball pitch is quite different from a good baseball pitch. If you've seen fast-pitch softball, you know that styles such as the 'slingshot' and 'windmill' deliveries have evolved, to take maximum advantage of this motion. The fact remains that softball pitchers are doing the best they can in a game whose rules are stacked against them.