Every pitcher I instruct wants to learn how to throw a curveball, and for good reason. The curve, when thrown properly, is a very effective pitch that hitters have been struggling with for years. Great curveballs are nearly impossible to hit. As a hitter you just don’t want to miss a fastball opportunity or you hope for a hanger you can put some barrel on.
Being a pitching instructor for as long as I have, I’ve gotten plenty of parents asking me to teach their son how to throw a 12-6 curveball. Well, I can’t! Why? Because very few pitchers throw with a 90 degree arm slot (required to throw a 12-6 curveball). Most arm slots are three-quarter. My arm slot is also three-quarter and I threw a great curve in my day. It wasn’t a 12-6 that dropped straight down off “the table”, but it was effective as it moved in on lefties (6-8 inches) and away on righties (6-8 inches).
Many coaches teach pitchers to raise their throwing arm up at least to a 90 degree angle and come down aggressively to get the necessary rotation on the ball to curve. The problem with this is, for most pitchers, you are changing their natural arm slot to throw a curve. You are putting their arm at risk of injury to throw a curveball when you do this. There is a better and healthier way to throw a curve than to change your arm slot.
The point I want to make is that you cannot throw a 12-6 curveball if your arm slot won’t allow it. Here is the video we made about how to throw a curveball correctly. It also explains what not to do when throwing a curveball to avoid arm problems.