Quick notes from me:
- playing normal in play-offs is risky, but later can give you advantage
- almost everyone are playing crunch time in play-offs so your enthusiasm should be even
- 1-3-1 is very risky
- he bought Center before play-offs and his rebounding rised
- your 1-3-1 and his 2-3 and you'll get raped on the boards
- you've been playing only Look Inside lately, and that makes your predictable
- he has better inside defense, so outside offense against him is way to go (atleast in your case as he probably expects you to play LI)
So unless he reads forums, if I were you I'd go with 3-2 defense and either Run and Gun or Motion (depends from your players), but that's just me.