Thursday, September 24, 2009

NFL Week Two Performance Rankings

In our articles, we often refer to our “Relative Performance Measure” or (RPM) which is the statistic we use to make up our performance rankings. Unfortunately, it is impossible to explain our RPM fully in each article, but we do get questions from readers such as “What is your RPM?” and “Why is it significant?”

Since it is early in the season, and there are only two games to go on with our RPM, we thought we’d take the time here to explain what they are, and why they are significant.


What are the PossessionPoints.com RPM numbers?

This may take some time to explain, so be patient and stay with us. You won’t be sorry.

The basic PossessionPoints.com stat is an offensive measure. It is a blended stat (which means it is generated by a mathematical formula from other stats and game information). As the name implies, “time of possession of a scoring drive” and “points scored on a drive” are key components. The quarter in which the points are scored also come into play.

As an offensive measure, we have key cutoffs at 60 and 100 (From analyzing numbers, we determined that 60 and 100 were significant levels where winning percentages changed.) This is where our color codes come in.

We turn an offense “yellow” at 60 and “green” at 100. From the time that we have been keeping this stat from the 2006 season, we have noticed that a team that gets to the “green” level of offensive performance, wins better than 75 percent of the time.

The defense of a team is measured by how many PossessionPoints it allows the opponent’s offense to total. The same key cutoffs apply, but this time we start a defense “green” and turn it “yellow” at 60 and “red” at 100. A team, that keeps its opponent below 60 (Green), wins better than 80 percent of the time.

We have talked about offense and defense but haven’t mentioned RPM yet. To get a “team” measure in a game, we simply subtract their defensive PossessionPoints performance from their offensive performance. This net number can be positive or negative and has its own significance.

You’ll note the 40-point yellow range in the offensive and defensive numbers. That range has significance here also. We color the net “green” at positive 40 and “red” at negative 40. Here a green net equates to better than 90 percent winning. This net number is a single game “Performance Measure.”

Our season “Relative Performance Measure” is the average that a team has performed in all of the games they have played.


Why is the RPM significant?

This is an interesting question because different people find significance in different numbers so we will look at a couple of things. As you know, 12 teams make the playoffs each year. Based on end-of-regular-season RPM’s, eight of the top 12 RPM teams in 2006 and 2008 made the playoffs, and 10 of the top 12 in 2007 made the playoffs.

In 2006 and 2007, five of the seven teams with the lowest RPMs to make the playoffs lost their first game, and in 2008 six out of seven lost their first game. In 2008, three of the top four were in the Conference championship games, and in 2006 and 2007 it was two out of four.

Another way to look at significance is to look at a team that this season is defying the PossessionPoints stat, and is 2-0 despite a very red -66 RPM. That team is the Colts.

In 2006, the Colts went 12-4 and won the Super Bowl. They finished the regular season with an RPM of 17 which was tenth in the league. They owe it all to their offense who was first with an average 134 PossessionPoints per game. Their defense was dead last with an average of 116 PossessionPoints allowed. But they won it all.

However, if you remember, their defense came alive in the playoffs and performed to an average of just 53 PossessionPoints allowed in the Playoffs. So, there was no surprise that this new-found defensive strength coupled with their famed offense, proved to make the Colts unstoppable that year in the Playoffs.

In 2007, the Colts as a team did better in the regular season with an RPM of 29, but their offensive performance fell a little to 124 while their defense improved to 94. They went 13-3 and got a first-round playoff bye. They met the 11-5 Chargers who had the No. 2 defense that year and an RPM not far behind the Colts at 23. The Chargers’ prevailed 28-24, and the Colts were one and done in the Playoffs.

In 2008, the Colts were again 12-4 like 2006, but this time they were one of the few teams to ever make the playoffs with a negative RPM. Last season, they had a -6 RPM and had to travel to San Diego to play the Chargers in the first-round game.

The Chargers’ regular season RPM was 29. It was by no means a mismatch, but the Chargers did prevail 23-17, and the Colts were once again one and done.

We find significance in winning football games, but can a team win without following the PossessionPoints formula? Sure, it seems the Colts are trying harder than ever to prove it in 2009, but we wouldn’t count on it. More likely the Colts will take a deep breath, realize they are fortunate to be 2-0 and make fixes that will result in them performing better by our measure.


On to the Week Two Rankings:

As the season goes on and there are more weeks of data, we would stack our stat-generated “performance rankings” against any opinion-based “power rankings.” Early in the season with only two games done, many position changes for the teams are still ahead of us.

Does it surprise anyone that the Jets are on the top of the performance rankings after two weeks? The probability is that their numbers cannot stay this strong. An RPM of 100 is way more than the Patriots’ 2007 RPM of 83.

That RPM was off the charts for a full season. By comparison, last year the Steelers after the Super Bowl had the top RPM, but it was only 37. So, we have to believe the Jets will come back to the pack a bit, and the question we have to ask is that as they get reeled back in will they continue to win?

Behind the Jets are the Saints, while the Jets have been defense led (allowing only 23 PossessionPoints per game) the Saints as you probably have guessed have been offense led posting an average of 163 PossessionPoints per week.

It’s a long season, but those two teams are off to a great start. We could talk a lot more about the chart below, but we spent a great deal of space trying to answer some questions we have gotten in the past.


No comments: