A powerful swing takes a lot of effort but you also read to have a relaxed swing and „let the barrel do the work“. I think there is some merit to it. In the last years there was a lot of talk about turning the barrel early. The proponents of that theory want to accelerate the barrel back and down early using the forearms and elbows (supination, that „seesaw move“ of the front elbow going up and rear one going down). Now I think this is not quite correct because in the kinetic chain the lower parts have to fire before the upper parts.
Jason Ochart of driveline suggested that the supination shouldn’t start the barrel release before the shoulders reach their peak speed. That is an important point in „letting the barrel doing the work“, the trunk speed has to peak early in the swing to allow the distal parts of the chain to work correctly. This means you can’t power your turn all the way through contact. Strength helps but muscling through contact won’t help you much.
In a good swing the trunk rotation speed peaks around 50-60ms before contact and then it slows down. You can see in the early part of the swing the body will turn. The barrel will turn backwards but mostly tied to the tilt oft he shoulders and the „elbow move“.
No sup ?♂️ pic.twitter.com/8wkPR81Upu
— Jason Ochart (@JasonOchart) August 15, 2018
Just after this phase the supination sends the barrel downward and pulls up the knob.
https://imgur.com/a/JTP0IDt
After this move the bat should basically be ballistic. The arms may or may not extend and the wrists continue to unhinge but you shouldn’t supply power to the bat, all the hands now can do is guiding the bat a little if even that.
If you have to power the bat in this phase
https://imgur.com/a/Jyxti0k
you have not worked correctly in the frames before that.The swing should be like a vertical jump, a frame before contact is basically take off and from then on you just fly. You don’t want the bat to decelerate but a lot of good swings actually reach peak speed slightly before impact.
Here is Todd Frazier demonstrating that the bat is actually ballistic at contact.
Swing power is relatated tot he amounts of watts you can put into the barrel but peak force should occur early in the swing and actually precede peak speed. The swing is less like a deadlift and more like a snatch were you accelerate the bar and let it fly in the end.
As for drills you can do actual bat throws. Try to throw the bat slightly upward into the cage net. Another drill you can do is a two tee drill, put a wiffle ball on the rear tee that is placed slight behind your front knee and a real ball on the front tee that is slightly higher and a foot farther out front. Now try to hit the first ball as har das possible and hit the front ball on the follow through without using effort.