The first thing to learn about a curve ball is how to form the grip on the ball. You want your index finger and middle finger to get a grip on the seam of the ball. Exactly how you do this might vary depending on the size of your hands. If you have smaller hands it might be comfortable to sort of straddle the seam with your index finger and middle finger on either side of it. If you have bigger hands, you might have both fingers on one side. The key is simply to get pressure on the seam of the ball.
Your thumb should be making contact with the seam on the other side of the ball, again with the goal of applying pressure on the seams. The whole trick to a great curve ball is in creating massive spin. The more spin, the more it will curve, so the more pressure you can create on those seams the better.
You should have the horseshoe type shape of the seam almost fitting nicely into the horseshoe type shape of your hand when you have your curveball grip.
A great practice drill is to take your grip and then turn your hand over upside down in front of you. Squeaze your thumb and forefinger together, almost like you are snapping your fingers. The ball should squirt straight up in the air with a tight spin on it. This will train your hand to have the proper release and generate lots of spin when the ball leaves your hand.
There are different variations of a curve ball, but typically when someone refers to a curve ball, they are talking about a ball that will start up and curve straight down to the ground. Again, there are variations, but if a ball is curving to the side of the plate, it is usually referred to as a slider.
There are a couple different types of popular curve balls. There is the long, slow looper like Barry Zito throws, and there is the sharp diving one like Ben Sheets throws.
When Zito throws a curve ball, the hitter knows immediately that it is a curve ball when the ball is leaving Zito’s hand. What makes Zito’s curve ball tough to hit is simply the amount of break in the ball. You might hear it referred to as a “12 to 6” ball meaning it moves from 12 o’clock to 6′ o’clock.
When Sheets throws his curve ball, it stays straight for a while and then dives hard when it gets close to the plate. What makes his curve ball so effective is that the batter might think it is his fast ball until it is too late.
So, how do you decide what kind of curve ball to throw? Practice and see which kind suits your personality. If you like throwing hard, you might like the Sheets style and if you like throwing soft, you might like the Zito style. Both are extremely great pitches to add to your arsenal.