I look at it this way, if BOS only goes 3-3, is that good enough? Probably. Assuming that DET wins the division and the competition is HOU and CLE, if we go 3-3, that means both HOU AND CLE need to go 5-1 or better since we own the tiebreaker against both HOU and CLE. We do not own the tiebreaker over DET.
It gets more complicated if DET and CLE end up tied as CLE owns the tiebreaker over DET but DET owns it over BOS. It would only matter though if HOU somehow got ahead of BOS, CLE wins the division (outright or via tiebreaker), and it came down to BOS vs. DET for the last wildcard.
The safest thing for BOS is if HOU loses, but their remaining games are @LAA and @OAK. DET has @BOS and @CLE. It is not out of the question that HOU wins most of their remaining games and that DET falls back behind CLE.
Bottom line, root for DET over CLE, if DET can win the series vs. CLE 2-1 or 3-0, very good for BOS. And root for HOU to lose no matter who they play.
