The second part of the system is a bit more complicated, as it involves taking the underdog when they go from a negative situation to a positive based on the line. The first part of the system is done in the exact same manner as the first example, in that you take the winning percentages and use the divider of 20.
For example, if the 76ers have a winning percentage of .400 and the Clippers have a winning percentage of .320, the 76ers would be rough favorites of four points.
If the 76ers are at home, Philadelphia is favored by seven (+7) and one the road the 76ers are favored by one (+1). From the Clippers’ perspective, they are seven-point underdogs on the road, which is (-7), while at home, the Clippers are one-point underdogs (-1).
When you factor in the point spread, the Clippers have the possibility of going from a negative figure to a positive figure and could possibly be a play.
If the 76ers are favored by 8 to 9.5 points at home, the Clippers would be the play, as they go from (-7) to (+1). (Remember we exclude games where the point spread is 10 points or more.)
If the 76ers are favored by 2 to 9.5 points on the road, the Clippers would again be the play, as they will go from (-1) to (+1) or greater.
Once again, the same qualifiers of back-to-back games being tossed out and staying away from teams with an injured starter.
As with all systems, just because something has worked in the past does not mean it will work in the future. But the system is certainly something that should be tracked over the course of the season.