Okay kiddo, have you ever played with a spinning top? You know how it stays upright and spins around and around? Well, a gyroball is kind of like a spinning top that a baseball pitcher can throw!
You see, when a baseball pitcher throws a normal pitch, the ball usually spins forward off his fingers. But with a gyroball pitch, the pitcher makes the ball spin sideways instead! This sideways spin makes the ball move around in a really cool way, like a zig-zag or a curveball.
Now here's where it gets a little tricky to explain. You know how when you spin a top, it tries to stay standing upright? That's called "precession." It's kind of like the top is trying to stay balanced, or stay balanced in a certain direction. Well, when a pitcher throws a gyroball, the sideways spinning of the ball makes it do a kind of precession too! This causes the ball to move in unexpected ways and makes it harder for the batter to hit.
So, a gyroball is a really cool pitch that makes the baseball spin sideways and move in funny ways because of a type of precession. It's a tricky pitch to throw, but if a pitcher can do it well, it can make for a lot of surprised batters!