Last year, the Steelers went 13-3, but you would have lost money if you bet on Pittsburgh every week. Despite that record, the Steelers went just 7-9 against the spread. Since 1978, teams that have won games are 7706-1514-256 in 9,476 games against the spread, which means teams that win cover the spread about 83% of the time.
The biggest outlier was the 1986 Bears. You probably have heard of a team called the ’85 Bears, who stomped through the league en route to a Super Bowl title. The next season, Chicago went 14-2 but went just 6-10 against the spread! There were 7 games where the Bears were favored by at least 9.5 points and won the game but didn’t cover; that is, of course, a record. The only other teams with even four such games where they failed to cover were the ’98 49ers and ’07 Patriots.
The graph below shows, on the X-Axis, the winning percentage of all teams in all seasons since 1978. The Y-Axis shows their winning percentage against the spread. You can see the Bears as the low dot on the bottom right, at 0.875 winning percentage and 0.375 winning percentage against the spread.
A couple other teams stand out to me. The 2008 Lions went 0-16, of course, but were 7-9 against the spread (far left on the graph at 0.000 winning percentage, naturally). Detroit covered 7 times all in games where they were double digit underdogs.
And how about the team down at 0.188 on the Y-Axis but with a winning record? That must be a team that was supposed to be very good, and only wound up being pretty good? It’s the two-time defending champions from 1980. Pittsburgh missed the playoffs that season, marking the end of the team’s dynasty. Pittsburgh covered just three times that season: in week 1 as a 7-point favorite against Houston, in week 4 as a 13-point favorite against the Bears, and in week 13 as a 6-point favorite against Miami. The Steelers Pittsburgh was favored in 6 of 8 road games, winning three outright, but failing to cover in any of them.
Below are the results from each team in 2017:
| Rk | Tm | From | To | W | L | T | W-L% ▼ |
Count | vs. Line | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Minnesota Vikings | 2017 | 2017 | 13 | 3 | 0 | 0.813 | 16 | 11-5-0 | Ind. Games |
| 2 | New England Patriots | 2017 | 2017 | 13 | 3 | 0 | 0.813 | 16 | 11-5-0 | Ind. Games |
| 3 | Philadelphia Eagles | 2017 | 2017 | 13 | 3 | 0 | 0.813 | 16 | 10-6-0 | Ind. Games |
| 4 | Pittsburgh Steelers | 2017 | 2017 | 13 | 3 | 0 | 0.813 | 16 | 7-9-0 | Ind. Games |
| 5 | Carolina Panthers | 2017 | 2017 | 11 | 5 | 0 | 0.688 | 16 | 9-7-0 | Ind. Games |
| 6 | New Orleans Saints | 2017 | 2017 | 11 | 5 | 0 | 0.688 | 16 | 9-7-0 | Ind. Games |
| 7 | Los Angeles Rams | 2017 | 2017 | 11 | 5 | 0 | 0.688 | 16 | 9-7-0 | Ind. Games |
| 8 | Atlanta Falcons | 2017 | 2017 | 10 | 6 | 0 | 0.625 | 16 | 7-9-0 | Ind. Games |
| 9 | Jacksonville Jaguars | 2017 | 2017 | 10 | 6 | 0 | 0.625 | 16 | 9-7-0 | Ind. Games |
| 10 | Kansas City Chiefs | 2017 | 2017 | 10 | 6 | 0 | 0.625 | 16 | 10-6-0 | Ind. Games |
| 11 | Buffalo Bills | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 9-6-1 | Ind. Games |
| 12 | Dallas Cowboys | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 8-7-1 | Ind. Games |
| 13 | Detroit Lions | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 8-7-1 | Ind. Games |
| 14 | Tennessee Titans | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 8-7-1 | Ind. Games |
| 15 | Baltimore Ravens | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 8-7-1 | Ind. Games |
| 16 | Los Angeles Chargers | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 8-7-1 | Ind. Games |
| 17 | Seattle Seahawks | 2017 | 2017 | 9 | 7 | 0 | 0.563 | 16 | 6-9-1 | Ind. Games |
| 18 | Arizona Cardinals | 2017 | 2017 | 8 | 8 | 0 | 0.500 | 16 | 6-9-1 | Ind. Games |
| 19 | Cincinnati Bengals | 2017 | 2017 | 7 | 9 | 0 | 0.438 | 16 | 9-7-0 | Ind. Games |
| 20 | Green Bay Packers | 2017 | 2017 | 7 | 9 | 0 | 0.438 | 16 | 7-9-0 | Ind. Games |
| 21 | Washington Redskins | 2017 | 2017 | 7 | 9 | 0 | 0.438 | 16 | 7-9-0 | Ind. Games |
| 22 | Miami Dolphins | 2017 | 2017 | 6 | 10 | 0 | 0.375 | 16 | 5-9-2 | Ind. Games |
| 23 | Oakland Raiders | 2017 | 2017 | 6 | 10 | 0 | 0.375 | 16 | 5-9-2 | Ind. Games |
| 24 | San Francisco 49ers | 2017 | 2017 | 6 | 10 | 0 | 0.375 | 16 | 9-7-0 | Ind. Games |
| 25 | Chicago Bears | 2017 | 2017 | 5 | 11 | 0 | 0.313 | 16 | 8-7-1 | Ind. Games |
| 26 | Denver Broncos | 2017 | 2017 | 5 | 11 | 0 | 0.313 | 16 | 4-11-1 | Ind. Games |
| 27 | New York Jets | 2017 | 2017 | 5 | 11 | 0 | 0.313 | 16 | 9-6-1 | Ind. Games |
| 28 | Tampa Bay Buccaneers | 2017 | 2017 | 5 | 11 | 0 | 0.313 | 16 | 6-9-1 | Ind. Games |
| 29 | Indianapolis Colts | 2017 | 2017 | 4 | 12 | 0 | 0.250 | 16 | 8-8-0 | Ind. Games |
| 30 | Houston Texans | 2017 | 2017 | 4 | 12 | 0 | 0.250 | 16 | 7-9-0 | Ind. Games |
| 31 | New York Giants | 2017 | 2017 | 3 | 13 | 0 | 0.188 | 16 | 7-9-0 | Ind. Games |
| 32 | Cleveland Browns | 2017 | 2017 | 0 | 16 | 0 | 0.000 | 16 | 4-12-0 | Ind. Games |
| Total | 2017 | 2017 | 256 | 256 | 0 | .500 | 512 | 248-248-16 | ||
Most surprising to me? Seeing the Rams — who had been underachievers for years — go 11-5 but just 9-7 against the spread. Then again, they broke Vegas right away, and it appears as though the books adjusted quickly.