2-seamer Vs. a 4-seamer - Carlos Gomez Thoughts

Since we got into a discussion about these pitches, I thought I would ask the expert: Carlos Gomez. He posts his regular column "Bullpen Mechanics - A Scout's View" on The Baseball Factory plus has written columns for The Hardball Times as well. I also asked him about young pitchers and breaking pitches. He was gracious enough to answer, which I cut out his e-mail and pasted here:

It seems unlikely that Lincecum throws only 2-seamers. I've been wrong before, but it doesn't make sense to me.

2-seamers generally have more movement. Most, if not all, sinkers are thrown with a 2-seam grip. 4-seamers are generally the pitch that hard throwers employ when they are trying to blow the ball past the hitter and have him swing under it. 4-seamers tend to stay up more than 2-seamers so it is a power pitcher's fastball.

IT seems unlikely that Lincecum throws only a 2-seamer, but if he doesn't, and is able to learn to throw a 4-seamer effectively, he should be able to throw more fastballs upstairs past hitters. A guy with Lincecum's arm slot and velocity should really throw mostly 4-seamers in my opinion.

There is evidence that in young pitchers whose arms aren't fully developed that throw too many curveballs, their forearm bones (radius, ulna?) develop abnormally. Breaking pitches that are thrown incorrectly are very stressful on the arm. More than anything, it's the incorrect technique of the pitch and probably not the pitch itself that hurts the kid. Until I get better info and research, I won't let kids throw curveballs til age 13 or later (depending on development).

Hope that answers your questions. That game was fun watching last night. Those two are the best examples of the mechanics that I advocate.

Carlos

Thanks again to Carlos for his informative response, I greatly appreciate it. It confirms what Mike Krukow said in his morning radio show, that as good as Lincecum is now, already blowing away guys, he hasn't even learned to use a pitch that would make him that much harder to hit. Boggles the mind how good he can become.

I feel like screaming "pinch me, I must be dreaming!". :^)