The throwing motion is not 'natural' and differs in baseball vs soccer countries.

[pampango]

I've often wondered how well boys or men who grow up in soccer dominated countries throw compared to Americans. bWe take it for granted that boys will grow up throwing balls as well as rocks, but in most of the world they grow up kicking them instead ...

What's odd is that you would think the act of throwing was something so basic that we were built for it; in this way it's not quite like riding a bicycle. ... That is, you would think that the motion was more or less natural -- capable of being improved upon, certainly, but roughly inherent. It is not. ... Also, fathers aren't throwing in the back yard with their kids enough, at least in my town. I've seen boys as old as 12 who throw a baseball like they are shot putting an ostrich egg.

But come to think of it, I have not seen that many people in mainland China or Europe throwing, as opposed to kicking, balls. Japan and Taiwan, on the other hand, have big baseball traditions and lots of accomplished throwers.

From a mother of a daughter:

I didn't think twice about marrying a guy who throws like a girl because I threw very well and would be the go-to athletic coach parent.I didn't count on coming down w/ inherited autoimmune arthritis. I gotta pop some tylenol and teach my girl how to throw. Thanks for giving me the motivation. She throws even worse than my husband, and I didn't think it was possible for anyone to be worse.

http://www.theatlantic.com/entertainment/archive/2012/09/throwing-like-an-american-throwing-like-t-rex/262713/

I was a baseball coach for many years and know that learning to throw 'the right way' takes a lot of practice. I had never thought about the fact that in soccer countries (most of the world) learning to throw 'the right way' is irrelevant.

There are many more anecdotes and quotes from Fallows' readers at the link.

[cthulu2016]

1. Throwing side-arm is more powerful, but not as accurate.

One seldom sees people around the world throw overhand. It is very hard on the arm, and depends on the shoulders rather than the pecs.

But by bringing the thrown object level with or over the eyes it is a little better for aiming, whether darts or footballs.

Sidearm pitchers in baseball who master control have long, healthy careers, but it is discouraged as "odd"

[Blue_Tires]

3. Not just that, but there are a number of pitch types and grips

that can only be done overhand...

I played baseball in high school, and my trig teacher was also the softball coach, and we had the longest, most contentious arguments over his assertion that underhand was the more "natural" way...Maybe after all these years he had a point

[cthulu2016]

5. Bill James wrote a cool essay once about side-arm in MLB, historically

It was one of those cases where the prejudice against it was so great that anyone who could do it was considered a one-of-a-kind freak... even though there were always a number of them in the majors at any given time, and some in the hall of fame.

The shoulder and elbow stressing overhand allows for a little more speed and accuracy and, as you note, more grips and faster wrist-snapping rotation, but all of that is offset by the fact that the side-arm or underhand pitcher has a naturally deceptive approach and a lot of natural movement. And with practice, the non-overhanders had fine control stats. Few walks.

The perfect pitch to hit is a batting practice fastball. You follow the pitch from a high release point right to the bat. A side-arm pitch is shielded by the pitcher's body longer and you cannot tell readily how much it is rising or sinking.

We think of relievers as needing the best stuff, but because the side-armer can pitch every day (literally) he becomes a natural for long relief. Then if he's really good he becomes a middle-man and closer. But if his stuff is so hittable why is he an ace closer?

But it would be rationalized... the "tricky" delivery was a good change of pace for one inning, but as a starter hitters would get used to it. Always rule of thumb in baseball.

It's funny that Dennis Eckersley became the best closer in the game only after wrecking his arm as a starter. A lot of the 1970s-1980s relievers had unconventional less-stressful deliveries.

But Bill James biggest interest was, if you could find a side-arm pitcher who was a good starter (not Sandy Koufax, just good) you could start him three times a week, and a good starter three times a week has great value.

The very *best* pitcher will probably always be an over-hander but nobody has a pitching staff of the very best pitcher. Teams win and lose in a 162 game season as much for reliability and depth of pitching as for theri aces.

[musiclawyer]

8. I think you meant Dennis Eckersley

of the great Oakland A's teams of the late 80's early 90's

Note: the United States is a bona fide soccer country, though it still might be considered niche sport status to many. Many kids are no longer taught to throw properly, replaced by just as many if not more kids who are now only taught to kick. If you did not know that there are even more ways to kick than to throw, then you probbaly are not a folllower of professional soccer.

[cthulu2016]

10. D'oh! Yes, thank you, the reliever, not the football coach

[Blue_Tires]

11. Not to mention the "submarine" style that can give hitters fits

I personally never liked seeing it as a batter

[upaloopa]

2. If they played baseball in soccer countries, kit

kids there would learn to throw like us.

[Blue_Tires]

9. Countries like Mexico, Venezuela and Holland are doing all right with their baseball talent...

to name a few...

[MineralMan]

4. I never played baseball,

but still learned the overhand pitching throw anyhow. It really was the best, most accurate way to throw something. I was pretty accurate with rocks. Once, as a teenager, I was working clearing brush with an older man who I worked with. We spotted a clearly rabid skunk about 100 feet away, walking in our direction. I picked up a nice-szed rock and threw it at the skunk, hoping to send it off in another direction. Instead, I hit it in the head. We buried it there, without ever touching it. I always could hit things with a thrown rock, for some reason.

That throwing style has been used for millenia when accuracy and speed are important.

[Blue_Tires]

12. Which is funny because as a child I *only* knew how to throw underhand

I thought that was the better way until I got into pee-wee baseball...

[MineralMan]

14. I grew up in a neighborhood with a full age range

of neighbor kids. We all learned from the older kids. We learned to ride bicycles, how to roller skate, how to throw, and much, much more, from kids a couple or three years older than we were. It was the baby boom, so there were kids everywhere, and the rule was that kids lived outside, except at mealtimes. Since it was California, we were outdoors whenever possible, in that small town in California. Parents were only there to provide food and a place to sleep, as far as we were concerned.

We were free-range children. Note: I was born in 1945.

[AngryAmish]

6. My god Kent Tekulve got old

This pic is five years old. Maybe he didn't get old, I did.

[aint_no_life_nowhere]

7. When I was 15, I spent a year at high school in France where rugby and soccer are king

but I was surprised they could really throw a ball hard. In gym class they were playing a lot of German style handball with a similar overhand throwing motion to American baseball where you score by getting the ball by the goalie into the net.

[obamanut2012]

13. Handball is really big in a lot of "soccer countries"

And, the throw is very similar to baseball's.