When should my son begin to throw a curveball?

This morning, a reader asked me, "when should their son begin to throw a curveball?"  The kid in question is 14, and had just attended a pitching clinic in which he was taught how to throw a breaking ball correctly.  As a result, his Dad wanted to know, "did I feel he was ready to begin throwing this pitch regularly or should he wait until a later age?"

My general rule on when to begin learning a breaking ball is based on the physical maturity of the youth. And the basic rule is "if they are shaving, they can learn and throw a breaking ball."

However, I'm a much bigger fan of the slider or a cutter (which is a pitch with an arm action very similar to the fastball) rather than the curve (which puts a lot of torque on the elbow.)  But if you/he do decide to begin working on a breaking ball, bear in mind, I recommend he only throw it with two strikes for now (that way, he will continue to develop his fastball/change early in the count), or bookend it (meaning throw it as the first pitch and last pitch to their best hitters).  This way, he can learn the breaking ball successfully, pitch well, and still continue to develop his fastball (extremely important to long-term development) and his change-up.