Turn the clubhead over instead of holding it off
For the driver, Bryson DeChambeau says the way to swing at max speed is to fully release the clubhead - 'turn the head over as hard as possible' - rather than holding the face off out of fear of a miss left. He frames committing to that full release, instead of holding it off, as where the added speed comes from. Presented as his own feel and intent, not a mechanical instruction.
Channel: Bryson DeChambeau
Watch official source at 48:54Why this context matters
End-of-round exchange in which Bryson and Romo compare drivers and talk about releasing the clubhead versus holding it off.