December 11, 2016

Outside Foxborough – Undefeated Numbers

fo.jpgBy Bill Barnwell
[email protected]

Although the Cowboys almost didn’t make it, their narrow victory on Monday does present us with a rarity coming up this week: a matchup of two teams, both 5-0. In fact, since 1983, there’s been exactly one 5-0 vs. 5-0 game, and it also involved the Patriots. In 2004, the 5-0 Patriots met the 5-0 Jets in Week 6. The end result? A 13-7 victory for the Patriots, and while both teams made the playoffs, the Patriots won the Super Bowl. So, then, if the Patriots beat the Cowboys this week, we can just pencil the Patriots in as champions and move on with our lives, right? No? Oh, statistics are annoying.

Obviously, there’s much more to the whole winning-the-Super Bowl-thing than going 6-0 and beating a 5-0 team. What we can do, though, is attempt to quantify what going 6-0 instead of 5-1 might do for the Patriots.

To do that, we’ll take the game-by-game records of every season from 1983-on, excluding the strike season of 1987. We’ll do game-by-game instead of week-by-week so that performances match up over the different bye week patterns that we’ve seen throughout the last 20+ years.

First, let’s see how likely a team is to even be 5-0 in the first place.

From this, we can see that 5.4% of teams have been 5-0 following Week 5. That means that that, on average, we could expect 1.72 teams a year to start their seasons 5-0. Now, you can understand how unlikely it is (a .28% chance, actually) that two 5-0 teams would be meeting when there’s not even a 50/50 shot of two 5-0 teams even existing come Week 5. In 2006, only Indianapolis and Chicago were 5-0, and in 2005, it was only Indy.Remember that this is based on real data, not simulations, so while there’s obviously a chance of a team going 16-0, because it hasn’t happened in the timeframe, 0.0% of the teams have won 16 games out of 16.

While it’s good to know the Patriots are one of a rare breed, what does that mean? Well, what we can do is compare those winning percentages week-by-week to a team’s end result; namely, how many wins did a team that started the year 5-0 average?

So, then, the Patriots catapulted themselves from a team that averaged 11.3 wins per season last week to one that now averages 12.2 wins per season. If they were to beat the Cowboys next week, they would go even higher and average 12.7 wins per season, but if they lose, they pretty much are back to where they were following their fourth game.

The bigger question, then, is what that means for the Patriots playoff chances. How often do teams that win 11 games make the playoffs? Or, alternately, how often does a team that starts 5-0 make the playoffs?

So, a team that wins 11 games will make the playoffs 98.1% of the time. The only 11-5 team to not make the playoffs in the course of this study were the 1985 Broncos, who missed out on a tiebreaker to two other 11-5 wild card teams, one of whom was, of course, the Eason Express.

On the other hand, a team that goes 5-0 will make the playoffs 94.1% of the time. A team that goes 6-0 will make it 96.0% of the time, but a team that’s 5-1 will only make it 85.4% of the time.

Finally, using this data, we can actually answer the age-old question. What’s the most important game a team can play? Judging by the playoff percentages, it’s actually a tie. In Week 9, a 4-4 team can really determine its destiny with its performance. If they lose, their odds of making the playoffs are a woeful 11.8%; if they win, an even 50%.

That 38.2% difference based upon the outcome of a sole game also comes up, not surprisingly, in Week 16. An 8-7 team is on the hotseat this time. Win, and you’ll make the playoffs 50.7% of the time; lose, and it’s only a 12.5% shot. Maybe some games really are more important than others.

Comments

  1. “Finally, using this data, we can actually answer the age-old question. What’s the most important game a team can play? Judging by the playoff percentages, it’s actually a tie. In Week 9, a 4-4 team can really determine its destiny with its performance. If they lose, their odds of making the playoffs are a woeful 11.8%; if they win, an even 50%”

    Thats a cool finding, the game 16 change seems apparent when we’re all watching those 8-7 (NFC) teams playing to see who makes it late in the year. But for so much to ride on game 9 for a 4-4 team isn’t so obvious.

    Since you need 9 wins to have a 50-50 shot, the 4-4 teams need to go 5-3. The team that goes 5-4 only has to go 4-3 to get their 50% 9-7 record shot at the playoff. The team that goes 4-5 has to go 5-2 over their last 7.

    It makes sense when it’s laid out in a chart like that, but I wouldn’t have guessed that otherwise.

  2. Actually, there’s a pretty consistent “knee” in the curve all season long at playing .500 football. There is a sudden 30% point or more drop off on either side of that line all year long. There’s nothing special about week 9 when you compare it to all the other weekly drop-offs for going just one game below .500:

    week 2 – 27.9
    week 3 – 32.4
    week 4 – 22.1
    week 5 – 31.6
    week 6 – 28.9
    week 7 – 28.7
    week 8 – 34.4
    week 9 – 38.2
    week 10 – 37.7
    week 11 – 30.5
    week 12 – 32.7
    week 13 – 28.5
    week 14 – 28.2
    week 15 – 28.2
    week 16 – 38.2

    The real lesson here is – stay .500 (or just above it in odd weeks) as long as you can and you’ll always have a near 50-50 shot at making the playoffs going into the last weeks.

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