Wednesday, August 23, 2017

Revisiting Losses to FCS Teams

As I mentioned last week, three years ago I imparted some gambling advice. Teams that lost to FCS schools should be avoided like the plague in their next game in regards to the point spread. Teams that lost to FCS schools had a cumulative ATS record of 30-33 in their next game. This cover percentage of 47.6% meant that betting against them was nearly right on the break-even mark and provided no value. Has anything changed in the last three seasons?
Over the past three seasons, losing to an FCS school has meant positive value the next week. Over 25 games, these teams have covered 64% of the time. What if we further parse the ATS records by role?
Underdogs provide pretty much all the value here. Teams that lose to FCS teams have not been favorites often in their next game. In other news, water is wet.

Here are the ATS records for teams in such situations by year with a rolling three-year cover percentage thrown in.
Over the past twelve seasons, teams that lose to FCS teams have covered right around the break-even percentage in their next game. The rolling three-year cover percentage has been all over the place indicating this might be a random walk.

The next two tables will break out the yearly cover percentage for teams in this situation by their role. We’ll start with underdogs.
Underdogs make up the bulk of teams in this situation. Losing to an FCS team probably indicates a team is not very good (though there are some exceptions), so seeing them in an underdog role the next week is not surprising. Underdogs have covered slightly more often than the break-even percentage, but again the three-year cover percentage has been high and low in the last twelve years. What about favorites?
Teams that lose to FCS teams have been favored the next week just eighteen times since 2005 (one and a half times per year), so sample size is an issue here. In seven of the twelve seasons, either zero or one team fit the criteria as a betting favorite the next week. If you had bet against the favorites in every game since 2005, you would have turned a decent profit (about 16.7% if you had made equal bets), but the small sample size precludes any valid statistical extrapolation.

Finally, to provide a better visual representation, here is a graph of the overall, underdog, and favorite rolling three-year cover percentage. I also included the break-even percentage as a point of reference.
If nothing else, the rolling three-year cover percentage seems to be trending upward since 2005. There are a few dips after the peak in 2010, but FCS losers appear to have at least a little bit of value in their next game. As always, handicap each game individually, but don’t outright dismiss a team that lost to an FCS foe.

No comments: