>He thought that analytics was changing the probabilities of discrete events by single digits.

That is actually huge in baseball. As an example, the player who was least likely to get a hit last year did it in 19.6% of their at bats (this typically isn't represented as a percentage and would instead be listed as .196 batting average), while the player who was most likely to get a hit did it 33.2% of the time, meanwhile the league average was 24.3%. That means "changing the probabilities of discrete events by single digits" is what separates the average player from the outliers at both the top and bottom of the talent pool.