A continued run of above average BABIP might be achievable because this lineup is hard to pitch to since it lacks a predictable profile By that I mean a fair amount of patience is leavened with aggressiveness very early in the count: see Ortiz vs. Betances for the HR or Hanley vs. Triggs last night for the double. Many of the hitters have also been doing a nice job foiling shifts, taking pitches away to the opposite field and finding the green spaces. The hitting coach seems to have them buying in to taking full swings through the ball which promotes balance and keeping the head on the pitch, helps generate hard contact, and reduces the tendency to just swing from the heels.
Building on that, by hitters in hot streaks:
Pedey's BABIP bump is pretty much being completely driven by grounders through the right side. His medium and hard contact is exactly the same. When he tries to pull it with runners on, he has been grounding into more double plays (8 so far. 6 all of last year, and on pace for a career high). I hope he keeps going oppo, and when he pulls the ball, keeps it in the air.
Shaw is actually hitting the ball softer than last year (down 8% from last year). His BABIP is up from all the up the middle and opposite field hitting (68% this year, up from 58% last year) which probably makes him that much harder to defend.
Bogaerts is hitting fewer line drives and more grounders (5% difference for both), but the hard and medium contact is up. Him pulling the ball more is a good sign, so he's actually beating shifts that way. He could probably benefit the most from being ever more aggressive on first pitch fastballs middle in, since his power is almost purely pull/left center. His BABIP may just always be high because of how great his approach is.
Bradley has been maiming baseballs as we've seen (10% harder but more grounders), but the distribution has been exactly the same as last year. It's nice that Chili thinks he has changed in that regard and is encouraging it, but the numbers don't back it up unless it has happened a lot more during this hot streak which could be more likely and the reverse of what he was doing while slumping.
Papi's BABIP is 30 points higher than his career rate, and is up 66 points higher than last year. It's mostly from him hitting more flyballs, and higher velocity because his soft contact is exactly the same as normal. It probably isn't anywhere near sustainable.
He has actually been able to pull the ball with more authority as well, so he is beating shifts using the Ted Williams style but that has nowhere to go but down.
Hanley is doing what he did last year. Career norms of distribution and BABIP. He is still hitting with much less authority in his time in Boston. The bomb over everything was nice, but this wRC+ of 115 may be what he is at this point.
Summarizing - Pedey, Bogaerts and Shaw seem to have bought in completely to hitting them where they ain't. Papi has been lucky as all get out, but lofting the ball like crazy which is making up for it. Bradley is hitting the ball harder than ever and some may be permanent. Hanley may have plateaued.
Holt, Mookie, Vazquez, Hanigan, have room to improve.
One other interesting note, is that the only lefty vs lefty or righty vs righty weakness (aside from Chris Young) is Shaw's .172 vs lefties. Everyone else is at or well above career averages vs pitchers with the same handed-ness (Pedey .302 vs. RHP, JBJ .327 vs. LHP) In fact, all righties have not been hitting lefties anywhere near their norms yet.
That could also be factoring into the increased BABIP, is the change in approach to combat weaknesses in their usual platoon splits.