When a player is nearing prime, you expect improvement not "regression to career norm, especially for young players who struggled out of the gate and then had 1.5+ decent seasons and are 1-3 years from peak prime.
Career norm is not an indicator of future performance for a player below peak.
Also, you keep mentioning Betts regression from his big year, but it doesn't explain why it was also less than 2015... same with Bogey & JBJ.
Look, I get that many under performances were injury related, but we had injuries last year and the year before, and a few of these guys declined two straight years at ages where that is rare.
Yes, I did put some of the blame on JF, and maybe that wasn't fair due to all the injuries, but it's not a mind construct to say there was widespread under performance, even if some was injury related.
Even, if there was 2:1 odds that each of 10 player would decline, you'd expect at least 2-3 guys to increase their OPS. We saw 1.
Leon, HRam & Pedi, yes. Fine to expect a decline, but even with those three, there were decent odds one might have a good year or at least even to 2016.
Yes, including Beni with his small 2016 sample size can be ignored, but all of Betts, Bogey and JBJ declining at once was clearly against all odds, when you look at their place on the age curve expectation charts.
I'm not a math guy, but if the odds that these guys would do worse were somewhere around this last March, we fell far short of performance expectations:
Odds of doing worse:
95% Leon (but would it be projected at a 200 point drop?)
70% HRam (...a 116 point drop?)
65% Young (but not a 141 point drop)
60% Pedey (37 point drop was not unreasonable)
50% Holt (a 179 point drop?)
40% Betts
40% JBJ
35% Bogey
Put all these together and it doesn't come to oh for 8.
I'm fine with saying due to injuries, they did not "under perform," and we'd be largely just be arguing semantics, but the fact is all but one guy declined, and it wasn't because they all had big up years or outlier seasons in 2016. Many did worse in 2016 than 2015 and worse in 2017 when compared to 2015 as well.