andrus on deck practice swing

Most MLB practice swings are bizarre and look nothing like their real swing.

What SOS said. It really is bizarre. Most cast their hands and swing downward off their front foot, completely contrary to their real swing at the plate. However, I have noticed most kids do this as well, even if they have good mechanics at the plate.

And many take those swings with a weighted bat, which I would never recommend. Traditions die hard in baseball.

Thanks for the responses... I've seen this from time to time at MLB, college, HS and club down to about 14's... was sure there was some mental hitting approach taught that I missed along the way (as a practice swing thought only).
GetAPitch.. Regarding the swing downward, I know that, back in the day, when my swing plane started getting too much of an upward plane, I would take those exagerated down swings. It seemed to help with "quick to the ball", "stay inside" and leveling the plane thru impact... of course, at the time, I was only thinking about getting rid of uppercut.

Most athletes warm up completely different than when they compete. Most of this is to loosen certain muscles before they get down to business. I wouldn't make too much of any athletes fundamentals when warming up. It is seen in most sports.

or you seen a hitter that swings level to the ball and not the ground.

How about this Heyward on-deck swing?

And Derek Lee...

thanks BobbyT.. now we're talking. Yeah, I get the Derek Lee thing. Could be Bottom hand/palm up, stay inside, stay connected w/ bottom hand elbow at contact, etc., but the Heyward move with the abrupt upward move is very similar to what I was asking about with Andrus. Not sure what the swing thought is. thanks for the great visual of what I was asking about!

Leverage's answer answers this question 100%. And what's wrong with Derek Lee in his clip?? Looks fundamentally sound to me.