It is hard to back test it, because no one knows the rankings at that time
that said, last year it was great, Kine (system originator) said 2 years ago was around .500 and 3 years ago it did well, those are based on backtesting it as best as we can
The thing that concerns me is it is mainly always the same teams we will be betting on and only be around 40 or so games
last year it went 18-3 on 1 Saturday, besides that was like .500