How to Bet on College Football: Look for Blowouts When Betting NCAA Football Second-Half Lines

One of the simplest contrarian philosophies in sports betting is "buying low and selling high," and there's no better time to profit from that strategy than during a game.

Bettors can capitalize on this approach by betting on NCAA football second-half lines in blowouts. I considered a blowout to be a margin of least 42 points by halftime, or the equivalent of six touchdowns.

When a team is down by at least 42 points at the half, you should bet them to cover the second half line. Seems crazy, right? Well, it works, and we've had the data to support it for years, via Bet Labs.

Since 2005, teams trailing by at least 42 points at halftime have covered the second-half spread at an incredible 64.2% rate, which is good for +31 units and a 22% return on investment.

Although the sample size is somewhat small (141 games over 13 seasons), the year-by-year results are consistent:

This simple system has been profitable in 10 of 13 seasons since we've been tracking second-half lines, and sportsbooks aren't really able to adjust.

When a college football team goes up big, it’s human nature to let up a little bit. In many cases, the team with the big lead at halftime is playing an inferior opponent and isn’t looking to completely embarrass it.

Huge leads can also motivate coaches to pull their starters to ensure that key players don't suffer injuries.

On the flip side, the team getting blown out is still playing for pride and trying to win the second-half scoreline. Even if the end result is basically determined, players will want to take something positive away from the game.

The window to bet second-half lines is very small and normally lasts only about 10-15 minutes. There’s very little time to analyze game data or to see how the market responds, and bettors must be quick to grab a line.

Generally, the public gravitates toward favorites who are already playing well, and this recency bias is very real in college football.

Since the 2005 season, we've tracked only three instances where a team down 42+ points at halftime received the majority of second-half spread bets.

It's easy to see why this happens from a public bettor's point of view. Most second-half spreads are low compared to the game margin, usually listed between +10 and +21 in these blowouts.

If Oklahoma dominates and is up, 48-3, over Kansas at halftime, public bettors will gladly take the Sooners to cover a second half spread of -14 of -21.

The mentality behind that is that Okahoma won the first half by 45 points, so the Sooners should easily cover a smaller number, such as -14 or -21, in the second half. Obviously that hasn't worked out so well for public bettors.

Speaking of Kansas, it's been a moneymaker in this position, going 6-0 ATS on the second-half spread when getting blown out at halftime. The Jayhawks have notoriously been a terrible bet overall, but this is a rare spot where they reward backers.

Teams down 42+ points at halftime are almost never favored in the second half, and it's happened only twice since 2005: Texas Tech (-3.5) at Iowa State in 2016, and Cincinnati (-4) at South Florida in 2015.

Texas Tech failed to cover as a second-half favorite, and ended up losing, 66-10, at Iowa State after being down, 45-3, at halftime. Cincinnati covered its second-half line at South Florida after going down, 51-3, at halftime.

Oddly enough, home teams actually aren't a great bet on the second-half line, going just 7-9 ATS, while road teams have gone 81-40-4 ATS.

You'll have to put on a brave face to bet the lowest of the low, but it'll pay off in the end.

One thing to keep in mind is that second-half wagers are voided/refunded if the second half is not "official." That could include situations where there's running time in the second half, or if the quarters are reduced from 15 minutes to 10 minutes apiece.

For example, in 2015, Boston College was beating Howard, 62-0, at halftime, so the coaches decided to play 10-minute quarters in the second half. Even though Howard covered +16 in the second half, any wagers placed on the second-half line were refunded in that game.