According to it's description it says it boosts the Pokemon's most proficient Stat after knocking someone out, but I was wondering if this meant the base stat, the in game stat (affected by IVs and the like), and if its affected by in-battle status moves.
Cuz, I just fought a Celesteela that got Baton Passed from Speed Boost Ninjask, and after it knocked out of my Pokemon, it's Beast Boost boosted it's speed. Which seems super weird, cuz I thought it was a slow Pokemon.