rotation of the shoulders
Food for thought...
The elbow positions you describe- front elbow up, back elbow slotting- is sometimes described as weather vanning. You may have heard this term.
I can't remember if Epstein uses it, or maybe one of the other hitting gurus.But is this elbow positioning a cause or effect? Is the swing plane made to match the pitched ball path by this weather vanning technique (cause)?Or, is the elbow position we see the result of other mechanics used during the swing (effect)?
There is documentation and theory that this elbow positioning is the result of other actions.
The theory goes something like this:1) Swing plane should closely match pitch plane.2)
The rotation of the shoulders during the swing should be perpendicular to the axis of the spine.3) For items #1 and #2 above to happen, there must be a pronounced backwards pelvic tilt by the hitter. By tilting the pelvis, the shoulder rotation can be BOTH perpendicular to the axis of rotation AND slightly upward to match the pitch plane.The degree of backwards pelvic tilt is greater for lower pitches, less so for higher ones.4)
It is the backward pelvic tilt that causes the front elbow to APPEAR to be going up, and the rear elbow to APPEAR to be slotting close to the rib cage.5) The elbow position described is an EFFECT of this pelvic tilt to get on plane with the pitch and not the CAUSE that makes this planar adjustment.Try this for yourself. Stand in your normal hitting stance, then tilt your pelvis so that your torso goes backwards.
You should see that the elbows will roughly get into the position described- front elbow up, rear elbow slotted.I hope that makes sense. Again, this is the theory of some hitting instructors and differs somewhat from Epstein's material.One absolute KILLER to a quick swing is if the rear elbow gets ahead of the hands. This can be a problem if the hitter is consciously trying to get that rear elbow in tight against the rib cage. This will create what some instructors refere to as bat drag.The resulting drag might actually produce a small increase in maximum bat speed, but will absolutely reduce bat quickness- the time it takes to get the bat from loaded position to contact.While the younger girls might be able to get away with this- and a host of other hitting flaws- as they progress and face tougher pitching, this reduction in bat quickness can be a fatal flaw.
In conjunction with the pelvic tilt to set swing plane I described above, here is another way to describe the elbow positions to get maximum bat quickness.Think of a four cornered box being formed by these four points: the batter's front elbow, the batter's hands and each of her shoulders.During the load and swing, try to maintain this box without collapsing it. You'll find that the elbow position will be very close to what Epstein describes, but this technique will eliminate the swing-killing bat drag that can happen when the rear elbow gets in front of the hands.But then again, that's all just one guys opinion! ;DWatch as much video as possible of the world's best hitters and I think that you will see many of these concepts for yourself.