40+ point differential in week one, and what happens next…

The Cowboys beat the Giants 40–0 in the opening game, what does history tell us about the rest of the season?

The Cowboys beat the Giants 40–0 in the opening game. This was the 9th biggest week one blowout since the merger, and the 14th biggest in NFL history. I took a look at what happens after such a big week one win/loss. What did these teams do in week two? How did their seasons end up? My data set is from the start of the 16-game era in 1978.

In week one of the 1991 season, Washington beat the Lions 45–0. Washington rode this wave of dominance throughout the season and went 14–2 and won the Super Bowl.

In week one of the 1999 season the Browns lost to the Steelers 43–0. Then they lost week two 9–26. Then they kept losing and ended up with the worst record in the NFL at 2–14.

These two examples are predictable and what the fan base was probably expecting after those week one games. But it doesn’t always go that way. More often than not a week one blowout signals how the season will turn out for the winner and loser of that game, but it’s not a slam dunk predictor. The team on the other end of that Washington blowout mentioned above was the Detroit Lions who put that 45-point loss behind them and went 12–3 the rest of the season, then made it to the Conference Championship (Losing again to Washington 10–41). There have been a handful of teams to win by 40+ in week one, and end up with a losing record. The Steelers who were on the winning side of that 43–0 game against the Browns mentioned above, went 5–10 to finish out the season.

• Since 1978, A team that wins by 40+ points in week one, has a season winning % of .603, compared to .411 for the losing team.
• A team that wins by 40+ points in week one, makes the playoffs 57% of the time, compared to 29% for the losing team. Keep in mind the overall rate is about 38%. So, the winning team has a 50% lift on that rate and the losing team has a 24% decline vs that rate.
• In week two that winner of the week one blowout went 3–4 and the loser of the blowout went 1–6.

Here are the games and the stats that followed that big week one win or loss:

Two obligatory caveats:

1. Small samples size alert (N = 7 games; N = 14 teams)
2. Week one is not different than week 4, 8, or 13. Its 6% of the season. There isn’t anything magical about week one, and although I didn’t do the work to prove this, I would assume we would see similar results if I did this analysis for any other week.