The first two clips of the girls swinging are what I would call finishing level. The plane of the bat crosses at about the same plane the ball is traveling. When they finish, their hands aren't low, but they aren't exaggerated like the girl in pink whose bat plane is very steep...granted, the ball is pitched low and the bat must travel in an arc to hit it, but as was mentioned, the on deck batter has the same swing, so it may have been a process taught rather than the position of the ball.
Here is a breakdown of what I was taught (and what makes sense to me). If your bat travels in the same plane as the ball, you can swing early and hit the ball, swing at the right time and hit the ball, and swing late and hit the ball. Since the planes match up, the batter WILL hit the ball so long as the timing is close.
If you swing on a plane different from what the ball is traveling, then there is only ONE point at which those planes intersect, which means that your timing must be extremely close to make contact with the ball, and pretty much perfect in order to hit the ball solid.
Here is a breakdown of what I was taught (and what makes sense to me). If your bat travels in the same plane as the ball, you can swing early and hit the ball, swing at the right time and hit the ball, and swing late and hit the ball. Since the planes match up, the batter WILL hit the ball so long as the timing is close.
If you swing on a plane different from what the ball is traveling, then there is only ONE point at which those planes intersect, which means that your timing must be extremely close to make contact with the ball, and pretty much perfect in order to hit the ball solid.