Came in way late on this one... But back to the weight distribution. Getting to far off your backside and onto your frontfoot before release is a gigantic problem for catchers. It makes a tremendous difference if you can maintain power on the backside when throwing down. It keeps your body connected and prevents your arm from being put in a compromising position (i.e. dragging). The day I learned how to stay back was the day I truly learned how to throw to second with authority, and coincidentally enough, my times dropped like crazy. The only problem with "gaining ground" is that the way it is taught to kids sometimes encourages this frontfoot weight distribution to occur because kids focus on gaining too much ground. If you focus on trying to hit that "center of the clock" your body's natural momentum will have you gaining a little bit of ground anyway.