I play men's fastpitch softball, and also played high school and amateur baseball. Although the basics of the game are the same, fastpitch and baseball are two totally different games. Fastpitch is a pitcher's game. Period. The motion of a fastpitch pitcher is less stressful to the arm (more natural motion), so pitchers can throw multiple games in a day (three or four is common, I believe the most I've seen was six). They say that a hard-throwing fastpitch pitcher would be comparable to a 110 mph fastball in baseball, when taking the shorter distance into account. I haven't done the math myself, but having faced some excellent pitchers, I believe it. If you're interested in watching some men's fastpitch, there are several leagues around the state, and tournaments every weekend. Inbox me for more info if wanted.