Press the trail hand on top
Fitzpatrick's trail hand is described as weaker and more on top, not palm-to-the-sky on the side of the handle. The coach says the force goes down on the lead thumb and thumb knuckle, with the thumb and pinch doing so much work that the last fingers can feel like an afterthought.
Channel: stayhandsy
Watch official source at 5:45Why this context matters
The coach calls this the cornerstone of the Matthew Fitzpatrick swing pattern.