And what are the raw records? I doubt these stats mean anything at all. JBJ has started 61 games, the Sox have played 74. So if instead of going 8-5 in those 13 games JBJ didn't start, they had gone 9-4, they're winning percentage would be .692.
True, the W-L doesn’t prove anything, but it leads to an interesting question about how much impact his defense has on games he plays vs. games he sits. And how much his bat does the same.
So I went game-by-game through the Sox season so far, and found that, the Sox have allowed 209 runs while JBJ is playing defense, and 76 when he hasn’t been in the outfield.
The Red Sox have 696-1/3 IP, and JBJ has played 572-1/3 of those defensive innings. Which leaves 124 defensive innings during which he did not play.
Which means the 2018 Red Sox have allowed 3.29 runs per 9 IP, when JBJ is patrolling the outfield. Furthermore, the 2018 Red Sox have allowed 5.10 runs per 9 IP, when JBJ is not playing defense. So that’s a difference of -1.81 runs per 9 innings pitched.
———
But his bat sucks, right? Well, not really, at least according to the reasonable expectations given his advanced batting peripherals. But sure, it does suck according to the actual outcomes.
So the Red Sox have scored 397 runs, and JBJ has been in the lineup for 317 of those runs, which have been scored over 569 offensive innings. Which means they’re scoring 5.01 runs per 9 innings of offense, when JBJ is an active batter in the lineup.
And when JBJ is out of the lineup, the Red Sox have scored 80 runs over 126 offensive innings. Which means they are scoring 5.71 runs per 9 innings of offense, when JBJ is not an active batter in the lineup.
———
So they’re +0.70 runs per 9 innings better on offense when JBJ is not an active batter in the lineup. But the team’s -1.81 runs worse on defense when he’s not playing the outfield.
I think the choice is obvious. The 2018 Red Sox have been a better team when JBJ plays, despite his woeful batting line.
That’s because his bat can be hidden by him hitting 9th, but team defense really suffers when he’s not playing the outfield.
And furthermore, I personally don’t see how the Sox have either the chips or the cap room to trade for an obvious upgrade over JBJ’s expected outcomes given his advanced batting peripherals; I don’t see that there exist anywhere in baseball an obvious upgrade over his defense, especially given qualitative factors like his familiarity working with Mookie in RCF, or in playing the Monster’s caroms in LCF.