In the baseball community there is a debate how the barrel turns to square up the pitch. At contact the bat is about perpendicular to the pitch flight and at launch it is at least 180 degrees away from that so the barrel needs to make about a 180 degree turn. Classic instruction wants the knob to go in the direction of the ball first and then in the end the barrel is turned by unhinging the wrists. This approach means there is a rather passive first 90 degree turn as the bat lays back to the catcher during the „knob to the ball“ and then there is supposed to be a wrist snap for the final 90 or so.
In recent years there is another theory that ommits the knob to the ball part, it basically says that the arms stay bent and the barrel is turned down and back actively from the launch position to „get on plane early“. This turn of the barrel is supposedly supported by the arms and hands, namely the back elbow dropping and fron elbow raising („the seesaw or „turn the triangle“) and also sometimes by a supination oft the top hand.
To proponents of the latter theory say their way is quicker and also helps to get on plane earlier while the proponents of the older theory say that the new one means casting.
When you look at the hand path from the side it is basically almost like a flat lying „J“. First is goes down in an arc and then almost level to slightly up. Using a race track analogy it is first a curve and then a straight. Now from above the hand path still will be somewhat curved as it follows the trunk rotation (although it does get slightly more linear because shoulder rotation slows down and the arms start to get pulled to extension) but from the side it will look curve then straigh. In the end then it will curve again as the bat pulls the hands over to the other shoulder (next curve of the race track).
Now my theory is that you should actually actively turn the barrel at the vertex point oft hat curve. That is actually when a race driver accelerates. If he accelerates earlier he will fly out oft he curve (cast) and if he accelerates later and waits until the straight he won’t get up to speed. So basically you actively turn the barrel down just before you get on the straight.
With the old school way you would wait until you are on the straight or sometimes even until you are before the next curve
This would basically be the point where you turn over the bat
You can see that the back elbow is almost down but the palm oft he hand still kinda faces the pitcher, so the hand is not supinated yet.
In the next frame then the knob gets turned up and the wrist supinated. The back elbow gets a little bit lower but most of the „seesaw“ and the supination are separated.
So basically it is switch the elbows while hands move slightly down (I like to say tot he „rear nipple“) and towards the end of that move (but not totally after it or it would be a two piece move) you snap the knob up to the sky (or more to the side with higher pitches where the bat angle is flatter). If you do that snap earlier you might cast and lack direction and if you do it later you might have late out front whip and being in the zone late.
So again in summary:
- Hands from the launch position to the rear nipple while doing the elbow seesaw and also tilt the shoulders but not open them too much.
- Towards the end of that move snap turn the knob and let the bat go through the zone with direction while also turning the chest towards the swing direction.
I have used that cueing with some kids I work with. This is of course just the hand path and bat path part of it, you also have to teach a balanced turn and other stuff like the load and getting to a good launch position but just for the hand and bat path I have liked that.