Reverse hand drill. That helps feel the lead arm straighten out.
SL
This imo would be a poor example of the reverse top hand
Could you please explain?
Absolutely - and please understand this is not a criticism of the player.
The tee is way out in front - watch her hands push to the ball. Later I will pull a slowed down GIF. But, when her hands pass her rear hip her barrel is way above her hands....her barrel finally gets to a "flat" position when her hands are in front of her front hip...
Hmmmm.....this could start another war, but all IMHO if you want to be long through the ball (which in my mind means a long hitting zone which means getting on plane early) you need to practice with a deep tee and learn how to hit line drives off this tee position....the sooner the barrel gets in zone and on plane (not meaning a chop down swing) the much better chance you have of staying there a long time....a big part of getting good on the deep tee is learning how to launch/turn the barrel rearward first with the hands/wrists/forearms as opposed to pulling the bat forward via shoulder rotation....
some examples