Now with Part 5 of our NFL trends, we are going to look at how rest affects a teams odds against the spread. If you haven’t, check out the Part 4 article on Streaks. In the graph below, we look at the rest differential plotted against the odds the visiting team covers. Rest differential is how much more time off one team has over another.
As we work our way towards the right side of the graph, the visiting team has more rest than the home team. Here there is a clear trend! When a visiting team has more rest than the home team, that is days since their last game, they are more likely to cover the spread. One would think that Vegas would take rest into account when setting their lines, but clearly visiting teams with rest are undervalued.
A good thing to note is how the trend is clear regardless of the amount of extra rest. It doesn’t just apply to teams coming off a bye week. A team that played Monday night or Thursday night, for example, could setup a situation where there is a rest differential of a few days.
Let’s take a look at the same situation but with the home team.
For some reason, the same trend does not hold in this case. With a couple extra days of rest, the home team has a higher chance to cover, but with 4 or more it’s about equal to the full population. It’s hard to say exactly why this is the case, but it appears Vegas does not correctly value home rest.