What two NBA stars and a betting scandal can teach us about humility, randomness, and the only edge that actually lasts in Investing. Picture this. Two former Boston Celtics — names once cheered in the Garden — being escorted by federal agents, faces hidden behind hoodies, the flash of cameras bouncing off black SUVs. Chauncey Billups, an NBA champion turned head coach of the Portland Trail Blazers, and Terry Rozier, now with the Miami Heat,both arrested in a sweeping FBI investigationthat pulled back the curtain on a sports-betting scandal that reads like a script too absurd even for Netflix.