I remember rooting for the Cubs (obviously it proved to be worthless) and the Braves back in the Maddux/Glavine/Smoltz/Avery days starting up the early 90's.
There were 4 of us (Gregorio, David, Hector and me) and our morning ritual consisted on visiting the local betting place every day. We had to walk 15 minutes and be there early in oder to get the best "lineas" (odds) and most important of all: your own copy of a "pitcheo" (piece of paper with today's games/times/schedules/pitchers & stats).
Was it legal at our age? Nop, but who cares. We were only 16 years old back then but placing a bet was easier and safer than buying a beer in a "colmado", also forbidden at that age but you know the deal.
After a couple of weeks visiting the place, the old folks got to know our faces and stopped staring at us.
Our betting patterns were really bad: Gregorio would always bet on the Cubs no matter who they were against with. Now remember that in 1996 they finished the year 76-86.
David & Hector managed to do OK. About me, let's say I was not as bad as Gregorio.