One important feature within Bet Labs is the 'Hide Duplicates' checkbox in the top right corner of the system builder.
Checking this off ensures that you never have a match on both sides of the same game. It's only necessary for systems that don't automatically rule out one side.
For example, if your system uses the home/away or favorite/dog filters, you've already ensured that only one side of each game can be a match. There can only be one home team or one favorite, which ensures there are never two matches on the same game.
However, some systems could occasionally have two matches, or 'duplicates', on the same game.
In the example below, you'll see a simple system that involves betting on very bad NFL teams in December.
What if two teams with a win percentage between 0% and 25% play each other, though? Both teams would be considered matches and the system would include both of them in its record.
When the 'Hide Duplicates' box is checked off, you'll see that 18 wins and 18 losses are removed from the system's record, which means that there have been 18 games since 2003 that have featured two teams with winning percentages of .250 or lower.
Be sure to check this box off whenever your system's filters don't automatically exclude one side.