Every single year as the playoffs approach, somebody, somewhere, is bound to whip out that old 'momentum' argument and suddenly everybody takes up the momentum story. Conventional wisdom would have you believe that teams that play well and win games at the end of the regular season are more likely to have postseason success.
Before we know it, we hear of teams 'peaking at the right time' if they win - but if they lose they were physically and mentally 'exhausted'. We see reports about teams that rested their starters, and if they lose they were 'rusty' and if they win they were 'healthy and well-rested'. Drives. Me. Nuts.
But what's even worse is that the arguments thrown out there that purportedly prove or disprove momentum are largely arbitrary, often anecdotal and almost always based on a negligible sample size. Arguments typically look something like this:
Pro: The Steelers rode a 6-1 regular season ending record straight to the Super Bowl in 2008. Momentum is important.
Con: The red hot 2009 Chargers, riding an 11 game winning streak, were one-and-done in the playoffs. Ergo momentum is overrated.
You get the idea. Momentum, Shmomentum ... after the break, we look at momentum in a little more quantitative depth.
Momentum
To find some statistical basis for 'momentum', I've chosen to look at the W/L records for all playoff teams in their final five regular season games, from 1978 to 2009.
I started with 1978 because that's when the NFL moved to a 16-game schedule and expanded the playoff field to 10 teams. In 1990, two additional wildcards were added to establish the 12-team playoff format we are still using today. Also, I've counted the two ties in that period (1997 Giants and 1978 Vikings) as losses to keep things simple. I have excluded all data from 1982, as that strike-shortened season saw a 16-team playoff field as well as the statistical oddity of two teams with a negative winning record (Lions and the 'real' Cleveland Browns) making the playoffs.
In total, that gives us 350 teams and their final five-game regular season records to look at in order to determine the effect of momentum.
Making the playoffs
Almost without exception, teams that make the playoffs have a winning record. It is therefore a statistically foregone conclusion that, more often than not, playoff teams have a winning record in their last five games. The stats confirm this:
| Playoff Team by record in last 5 regular season games, 1978-2009 | ||||||
|---|---|---|---|---|---|---|
| W/L record |
0-5 | 1-4 | 2-3 | 3-2 | 4-1 | 5-0 |
| No. of teams | 1 | 9 | 53 | 130 | 110 | 47 |
287 of the 350 playoff teams (82%) over the last 31 years had a positive W/L record over their last five regular season games. The 1986 Jets are the only team to enter the playoffs riding a five game losing streak. Somewhat surprisingly, they managed to beat the Chiefs - who themselves were coming off a three game winning streak - in the wildcard game that year.
Winning a playoff game
So once your team is in the tournament, is 'momentum' conducive to winning that first game? Not really, as the stats below show.
| Record in 1st playoff game, 1978-2009 | ||||||
|---|---|---|---|---|---|---|
| W/L record | 0-5 | 1-4 | 2-3 | 3-2 | 4-1 | 5-0 |
| No. of teams | 1 | 9 | 53 | 130 | 110 | 47 |
| Record in 1st PO game |
1-0 | 4-5 | 30-23 | 68-62 | 60-50 | 33-14 |
| Winning %age |
100% | 44% | 57% | 52% | 55% | 70% |
Somewhat surprisingly, the record in the last five regular season games has virtually no effect on the winning percentage in that first playoff game - except if you're rolling into the playoffs on a five game winning streak, but then again, those 5-0 teams are probably pretty good teams to start with and should be expected to win that first game.
So, momentum myth debunked? Not so fast. Every year, only the cream of the NFL crop make the playoffs, and frankly, it's not surprising at all to see about a 50% win ratio for most teams, after all, the other teams in the tournament are pretty good too.
Playoff success
After taking the hurdle of that first playoff game, we can observe a marked correlation between playoff success and the regular season ending record: The better your record in the last 5 regular season games the higher your likelihood of winning the Conference Championship or the Super Bowl:
| Playoff success, 1978-2009 | ||||||
|---|---|---|---|---|---|---|
| W/L record | 0-5 | 1-4 | 2-3 | 3-2 | 4-1 | 5-0 |
| No. of teams | 1 | 9 | 53 | 130 | 110 | 47 |
| Conference Champions (in %) |
0 | 0 | 7 (13%) |
16 (12%) | 22 (20%) | 17 (36%) |
| Super Bowl Champions (in %) |
0 | 0 | 2 (4%) | 9 (7%) | 10 (9%) | 10 (21%) |
Only two teams that entered the playoffs with a 2-3 record have won the Super Bowl , and both of them recently: the 2009 Saints who came in on a three game skid, and the 2006 Colts who also rode into the playoffs on a 2-3 record.
And in case you're wondering, the '92, '93 an '95 Cowboys Super Bowl teams were 4-1, 5-0 and 3-2.
The higher percentages of Super Bowl wins and Conference Championships for teams entering the playoffs on a 4-1 or 5-0 'hot streak' suggest that there is indeed something to the notion of momentum. Or are teams that have a strong season-ending record just generally very good teams?
We can split the 1979-2009 data a different way to find out. By separating teams that start the playoffs in the wildcard round and teams that enjoy the bye week and enter the playoffs in the divisional round:
| Playoff success, 1978-2009 | ||||||
|---|---|---|---|---|---|---|
| Teams | 1st playoff game win | Conference Champions | Super Bowl Champions | |||
| Bye-week | 146 | 94 (64%) |
51 (35%) |
25 (17%) |
||
| No Bye-week |
204 | 102 (50%) |
11 (5%) |
6 (3%) | ||
Teams entering the playoffs on a bye week have about the same chance of winning a Super Bowl or a Conference Championship as teams entering the playoffs on a 5-0 hot streak.
At the end of the day, it's fairly simple. Good teams win Super Bowls. Good teams win more games than they lose, and that includes the last five regular season games. If you want to call that momentum, more power to you.
***
Tip o' the hat to BTB-member dunkman for the initial thought that led to these posts. Oh, and "First!". First that is to mention 'momentum' in the context of the 2010 season. He he he.