Woah crazy prediction. Should be a DD win, so -5.5 is a good play, but then -235 is nothing at all to pay in this situation. Boston has had 3 days to think about blowing game 4, 3 days to grasp the importance of this game in what could be their last run.
This is a year Boston "has it", like 08 and 10. Game 3 shows what happens when they focus up. Game 2 in ATL w/o Rondo, down DD in the 4th and won. Major statement games to show the capability of this team. It's another must win situation here, playing at home vs. a Sixers team with little experience that isn't ready for this against such a veteran team that will be more focused than ever.
Since 08 Boston in the playoffs is
33-9 (79%) SU at home
23-7 (77%) SU after loss
16-1 (94%) SU at home after loss
6-0 (100%) SU at home in game 5
6-0 (100%) SU at home after losing last home game
-235 implies 70%. I'd honestly say no less than a 90% chance to win