I found the systems online once, with a little google search, as I became curious.
In the NFL it was:
If the underdog team playing at home is playing on a different type of surface than the away team’s home stadium, then bet for the home underdog team in the line spread to win.
According to the PDF it was 60% winners. I tested it to my database, and it was like 50% over 4-5 seasons.
NBA System goes like this:
1. Check the NBA schedule and mark down any series where one team will be
playing at least 3 consecutive games on the road versus a team of a different conference.
2. For the team that will be playing 3 or more consecutive games on the road with a different conference, make a bet A for the team on the road on its first day by buying 3 points.
3. If you lose bet A, make bet B on the next day for the same team, buying 3 points.
4. If you lose bet B, make bet C on the next day for the same team, buying 3 points.
I have not tested it with my own data, but as I said, somebody tracked it last year and it lost the very first series. You have to win something like 19 out of 20 series just to break even.
MLB is like this:
Check the MLB results and mark down any series where one team goes winless
versus the opposing team (a sweep)
For the teams that were swept (winless in those series), mark the schedule for their upcoming series versus the same team that swept them previously
3. On the first day of the rematch between the two teams, as long as the team that was swept previously has an RPI value of no less than .01 than the opposing team, AND the opposing team is not a top-3 RPI team, make a bet for the team that was swept. (Note: The RPI will be explained in greater details in a later section of this
manual)
4. If you lose bet A, make bet B on the next day for the same team
5. If you lose bet B, make bet C on the next day for the same team
And keep this in mind: ALWAYS bet on the money line if the team you’re betting on is the favorite to win (shows -1.5 on the run line). ALWAYS bet on the run line (+1.5 runs) if the team you’re betting on is the underdog (shows +1.5 on the run line).
I have not tested this either.
I have not played any of the systems. When somebody tells this system is amazing and will never fail, and I test the first system and it actually fails, I stop looking at the other "amazing systems" :-)
As Jefff sais, if you want to bet systems that OK, but never use Martingale to get back losses.