Need help with strike zone

[Heyblueguy]

All good advice. I could add (at least) one more piece: Keep your head as still as possible and follow the ball into the catcher's glove with only your eyes.

The most common thing that occurs if you're having problem with a strike zone is that you're calling pitches too fast. As was mentioned in other posts, don't even start to decide whether the ball was a ball or strike until you see the catcher catch the ball. If you do this, your timing will slow down and your zone will improve.