Yes, nobody expected Leon to repeat 2016, but we also lost two sub .500 catchers in Hanigan and Holiday, and most expected Vaz to improve on 2016, and he did. Overall, I think expecting about the same overall catching OPS was called for, and that's what we got.
Yes, we should not have expected Pedey to repeat 2016, when he's been under .800 in his other 3 recent years.
Yes, HRam has been inconsistent and playing injured for many recent years.
Moreland has been the Moreland of old.
While expecting HRam, Pedey or Moreland to do very well or great might not have been expected, I still feel the chances all 3 did not do as well as they could have done is slightly against the odds.
Now, to take those odds and couple them with the fact that every young- up and coming- player has declined from 2016-- all at once-- is surprising at least and shocking at most. These are players on the upward curve or expected growth. Sure, there is the possibility that all had outlier seasons last year, and this year was a just a return to their norm.
Yeah, maybe there is no simple explanation. Papi's departure and lack of his team leadership and positive affects on other players has to be part of the answer, but it is doubtful it is all of it.
I disagree on you JBJ call. While he did have an unbelievably slow start to his career, he had gone over 900 PAs with an OPS over .830 right before the start of 2017. He's right at the start of his prime. He's down 100 points from his previous 900 PAs. He has not been "like this for years", unless you truly think he is more like the rookie JBJ than the 2015-2016 JBJ.
Betts and Bogey, as you pointed out, should not have had years like this. Beni's sample size was too small last year to have any expectations of improvement.
I've mentioned this before, but I think it is worth repeating: looking singularly at any returning Sox player, nothing looks shocking, except maybe Betts. One could expect that we might see decline from 3 or 4 of these 6 returning players: HRam, Pedey, Bogey, JBJ, Beni and Betts. It was highly improbable for all 6 to decline, and shocking to me anyways, how much they all declined.
Last 3 years....
.717>.866>.749 HRam (-117/+32)
.832>.835>.731 JBJ (-104/-101)
.820>.897>.795 Betts (-102/-25)
.797>.825>.760 Pedey (-65/-37)
.776>.802>.745 Bogey (-57/-21)
n/a>.835>.778 Beni (-57/ n/a)
As you can see, all but HRam are down from their 2015 seasons as well. To me, this is shocking and unexplainable.
The other positions:
Catcher .646> .665> .695 (The only position with returning players that improved)
3B .693> .686> .676 (Pablo out- Devers in)
DH .855> 1.045> .748 (No Papi- replaced by Moreland at 1B & HRam to DH)
To me, the drop of by virtually everyone but Vaz is totally unexplainable and shocking by just how much many decline by. We're not talking 10-15 points. We're talking all 6 players going down by 57 or more points. 3 of the 6 by over 100!