At Augusta? Holing everything out?
I think you'd be surprised.And that's with golfers playing worse greens than PGA Tour players typically play.
Given enough time to adjust, every class of player (save the absolutely terrible, the 25+ handicappers) putts better on a faster green than a slower green. They three-putt more often, but they one-putt even more often than that. Three main reasons: 1) the ball can be rolling slower at the hole, so capture size is increased, 2) shorter strokes are required, so the player is making a stroke less prone to error, and 3) the ball isn't as likely to bounce offline due to small bumps or imperfections. Faster greens are smoother.
Those "average" stats don't work across all contingencies. Augusta's greens are pretty extreme. It might not be ten shots higher, but it's going to be at least 4 or 5.
I'd take that bet (no odds, though - it'd be a pretty fair bet), if the scratch golfers are given a few practice rounds (Tour players get them). And if they're Oakmont members, hell, they might not even need those.
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BTW the source of the 30% is
Every Shot Counts. But my own testing with Tour players, average players, etc. shows similar results.