Just a thought about PG and their "historical" Numbers. You need to look at sampling size too.
2017 will have a much larger sampling size than 2018...2018 than 2019 and so on. 2020 probably has only a handful of athletes listed and the reason a 2020 is already on their board is cause he is the best around.
What my point is, my hypothesis is 2017 numbers are made up of more "averages" then a 2020. This make sense or am I way off!!??
My 2020 threw off a mound and he's 5'8 and 135 (listed him summer time as 5'9 140). He hit 64 MPH with NO pitching training just throwing. Quick feet and he gets the throw down fairly well..I think he could at his best hit a 2.2 somewhere but it averages more like 2.3 or so. Just hoping on the growth spurt. They had him at a 2.4 last fall and he is throwing much better now....