Equal and opposite, Flex T position, whatever you want to call it, it works.
What is it?
It’s really a balancing act between your front (glove) arm and throwing arm. You need to make sure that the angle of your front arm matches your throwing arm angle. Okay, if that doesn’t make sense take a look at these MLB pitchers.
All of them use their front glove arm for balance. It’s hard to explain without writing a novel about it, so I’ll simply show you how MLB pitchers do it right.
Take a look at Detroit Tigers pitcher Justin Verlander (at 29 seconds). See how his front arm matches his throwing arm angle?
Here is a clip of Brian Wilson (at 12 seconds) for the S.F. Giants. His arms go further out than Verlanders, but check out the balance. I also want to point out how his head stays over his center of gravity all the way to foot strike. perfect.
Here are two more: