Wow.
Didn't realize my comment would stir so much trouble up.
Keep this in mind...if a kid is possibly good enough to play college / pro baseball, then yes they should probably look at specializing in baseball after they are in High School. That being said I didn't realize we were talking about just older kids. YOUTH (as in 9-12 year old) baseball with travel ball being so dominating, has started to tell parents and kids if they want their kid to play college baseball they need to get started now.
First off the percentage of kids that play college or pro baseball is a drop in the bucket. Next is the fact you have no way to project growth consistently. TOO many times I have seen the 10-12 year old stud player peak at that age. I wonder if when these guys turned 15 and they aren't getting any better, if they wish they had played other sports?
"Throwing to stay loose" ?
Any repetitive motion will wear on a body, much less a young body. Not resting the body for that motion is asking for trouble in many cases.
Not to mention the possibility that no parent ever wants to talk about...BURN OUT.
You don't think a kid will wonder what it would be like if he could go hang with his friends instead of go to private lessons? Go to the beach that weekend instead of play ball?
Some kids (and parents) have baseball become their LIFE. And again, parents get emotionally vested and tied to their young son's baseball. It usually doesn't end well if they can't realize it's not their baseball at all.
A poster mentioned kids from the Dominican Republic among other places. The big difference here? The majority of those kids come from poverty stricken backgrounds. Baseball is their dream to a way out. It's a means to an end. And for every Dominican kid who makes good in the MLB, there are probably HUNDREDS who end up hanging their cleats up in small towns across this country after making it to the minors IF THAT.
It would be wrong to compare a 'normal' kid here and a kid from that kind of background. The motivation is from a totally different source...and it's a totally different KIND of motivation.
I wonder how many kids playing baseball (or other sports) partly do it because of how important they perceive it to be for the parents. They want to please them.
Something to consider at least.
The other argument is "upside", as mentioned.
Take a kid who at 18 is fully grown. He's a good athlete, but he had been trained by the best coaches, he's fundamentally sound. He's SUPER polished. How much further is his "upside"?
Now take the kid who has athletic ability, is a good player, but never specialized or been truly instructed. What's his upside?
Which one of these kids do you think a Scout would perceive to have lots of room to "grow" as a player?
Just my 2 cents.