930 dollars.
That is how much you would have won if you threw down $100 on each NFL home team ATS this season. You did not have to handicap and seek out value. You just had to blindly bet home teams and reap in the winnings.
We are 91 games into this NFL season and home teams have beaten the spread 50 times, dropping only 37. For the mathematically challenged among us, that is a 57.5% win rate for home teams. This easily eclipses the 52.4% number you hear so much about when betting spreads.
So is this just a fluke or are there underlying reasons for this anomaly? That is the million dollar question. It is one that I will attempt to give a thorough, data-based answer.
Is the Schedule a Factor?
When dissecting a trend, it is important to cross our Ts and make sure there is not something obvious causing it. I wanted to first make sure there was not a scheduling imbalance that caused a lot of really good teams to play at home.
I broke down the records of teams in home games in 2018. The W-L column is actually “wins minus losses” or the difference in record. Obviously, the higher the number the better the team.
W-L | Games | ATS | Avg Line | SU |
4 | 1 | 1-0 | -3.0 | 1-0 |
3 | 2 | 0-1-1 | -4.2 | 1-1 |
2 | 7 | 5-2 | -5.4 | 5-2 |
1 | 17 | 9-7-1 | -2.6 | 11-5-1 |
0 | 31 | 15-14-2 | -3.3 | 17-13-1 |
-1 | 20 | 11-9 | -2.2 | 15-5 |
-2 | 9 | 6-3 | 0.0 | 6-3 |
-3 | 4 | 3-1 | 0.1 | 2-2 |
Very interesting. No imbalance here. Actually, bad teams have played more at home. Teams under .500 have played 33 home games while winning teams have played just 27.
If you showed me this breakdown without the ATS and SU records, I would have predicted that the home teams would really be struggling this year. Here is the crazy part: Not only are home teams winning ATS at an unusually high clip, but they are winning SU, as well.
This is awesome stuff for stats and number geeks. Right now, through 91 games, teams with one less win than loss are winning 75% of their games SU at home. Since we began collecting data in 1989, the highest win percentage for such teams over an entire season has been 64.9% in 2012.
It is not fair to compare numbers from 91 games to those accumulated over an entire season. Look at the first 6 weeks of an NFL season, and this 75% rate has been matched only three times: 2012, 1995, and 1991.
Can We Expect Regression Toward the Mean?
Since we only have these three seasons as precedent, we should try and learn anything we can from them. The first thing I checked is how these teams with one less win than loss fared at home after Week 6.
Year | Record ATS |
2012 | 4-9-1 |
1995 | 3-9 |
1991 | 10-5 |
So in 1991 these losing teams continued to roll. They sure fell apart in ‘95 and 2012, though. Once again, we need to know if this was a fluke or if we can expect a regression in 2018. I will expand the search to include teams that are either -1 or -2 in the record difference.
Here is a breakdown of their ATS records before Week 7 and then from Week 7 on.
Year | < Week 7 ATS | ≥ Week 7 ATS |
2012 | 56.7% | 36.7% |
1995 | 44.4% | 39.3% |
1991 | 52.4% | 60.9% |
You may not understand why I choose to display the numbers I do, but there is a method to my madness. If teams whose difference is -1 show one trend and those whose difference is -2 show another, it is probably a fluke.
There is not enough separating the two talent-wise to account for a big difference. Because the trends are consistent in my two tables, I have faith that we have discovered something real.
1991 home teams, especially the bad ones, defied odds all season long. Those betting on a turn-around probably lost quite a bit that year. I am confident that will not happen in 2018. Here is why I believe why we are safe to begin betting road teams this week:
Right now, really bad home teams (less than a -1 difference) are winning at a higher rate than they were in 2012, 1995, or 1991. In fact, these really bad teams were -EV bets in ‘91 and ‘95. Because home teams have been money this year, Vegas oddsmakers will almost be forced to alter their lines.
Word is going to spread that home teams are hot in 2018. Many are going to flock to their favorite books and begin blindly backing home teams. This means one thing to the bookies – make those odds worse.
Since Vegas will be receiving plenty of action on home teams, we can be assured we are getting tremendous value if we get ahead of the trend reversal and bet visitors.
Kreighton loves sports, math, writing, and winning — he combines all of them as a writer for WagerBop. His favorite sports to review are MLB, NFL, NBA, NCAAF, and NCAABB.
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