The three leagues I found I  can select a wager only based on the odds are the following: England Championship League, Bulgaria (main League), and Belgium Jupiler League.
When I say to select a bet according on odds only I mean that no other  variables - teams form, injury or any other info or news - is taken into account. I'll go deeper with direct examples. But I decided not to enter the numbers in details of my studio, - should be a reason to invite you to check by your self.

- Championship: Select all home wins in this league all season long as the home team has an average odds ranging from 2.00 to 2.50 - the only other condition is that the home team must have at least 1 home victory in head-to-head matches in the last 5 games played . (From the 3 leagues i showed here this is the only one that has a second variable as well as odds).

- Bulgaria: Select all home wins as the home team has an average odds ranging from 1.95 to 2.50 - no other condition is required for this league - just this range of odds for the selection.

- Jupiler League (Belgium) every time the home team has an average odds ranging from 4.00 to 5.90 - no other condition is required for the selection.

I invite you to check these Leagues on last 2 season, round by round.

In the examples thus indicated, betting in each championship on each match that meets these conditions will give us back a decent profit at the end of each season. If this system will be confirmed will give the advantage to be followed easily - without break your head to track news or having to analyze - (though it will require constancy in following it without jumping events or being discouraged by bad runs).
I will continue to test it in the current season but as I said at the beginning of this article, I will not use it in my betting system neither I will invest money - at least for the time being!