Three count (not the team)

Hi Scott,

Hope you’re well.

Over the years I’ve seen a handful of matches where the referee does a 3 count in the style of a boxing referee counting to ten.

Did WWF popularise the “slap the mat 3 times” style of pin count? Is it just one of those things that over time has just become the standard?

I've seen very few matches without the mat slapping.  Even the ancient stuff from the 40s and 50s.