How to throw on a downward plane off the pitcher's mound

Just about every pitcher has been told at some point in his career to "throw on a downward plane." Sound familiar?

But what exactly does that mean?

The degree of downward plane depends on a pitcher's natural arm angle. The higher the angle, the greater the downward plane. It is much more difficult for a batter to perceive and hoit a baseball that's coming in with a greater downward plane that it is to hit a baseball that's "flat." Therefore, the higher the arm angle, the more difficult the pitch is to hit. The smaller the downward plane -- such as the ball path of a sidearm pitcher -- the easier it is to hit it, all other things being equal.

Many sidearmers are sinker ball pitchers, which is how they achieve "downward" movement. But not too many sidearmers have good breaking balls. This is why.

Remember that it's important to find a pitcher's natural arm slot and not to change it in order to get more downward plane. (Of course, this would be done by raising the pitcher's arm angle up to a 3/4 or high-3/4 arm slot.)

That's because achieving the downward plane also encompasses proper arm and body mechanics. If the pitcher already has an arm angle anywhere around 3/4 and implements good pitching mechanics, he will throw the ball on a downward plane toward home plate.