Welcome to the second part of the NFL trends series. Here we’ll take a look at how your odds change when betting the total. First lets look at betting the over.
In the above plot, we look at the probability of winning an over bet when the total line is less than a particular amount. Along with this, we have 90% confidence intervals that are based on the sample size at each line (all points have at least 50 samples). As one may expect, betting the over appears to be best when the total line is small. For all cases (total line less than 65), the odds of winning by betting the over is about 48%. Looking at the other side of the graph, a total under 40 points has a 50% or higher chance of going over.
Let’s take a slightly different look at the odds of hitting the under.
An interesting point off the bat is the general odds of winning any under bet. At over 49% when including all cases (total greater than 25 points), the under bet has a higher chance of winning than the over shown before. Looking at high total lines, we have a trend that is near profitable. With a total line greater than 45 points, betting the under gives a historical winning percentage of just over 52%, essentially the break even point. On the edge of the plot at total line greater than 50 points we see a sharp decrease in winning percentage. This is likely due to smaller sample sizes, but I would be a bit weary of unusually large totals. In general, a good betting strategy is betting the under, especially on high totals.