One of the things that was beaten into us during our political science classes was the fact that you could not attribute causation in any human endeavor. There are just too many variables. What we can do is determine how strong one factor is correlated with another. If the correlation is strong then the stat is meaningful. Ultimately, that’s what we’re trying to do with The Value of Things. We want to find meaningful statistics.
Obviously, sometimes we will succeed and sometimes we will fail. Success and failure is also often left up to the eye of the beholder. We start with team statistics and move on down to the individual ones. As one commenter said in the last piece, there are just too many moving parts to attribute much significance to individual ratings. I don’t know how true that is, but we will run with that notion for today.
It’s easy to see how we can simply look at overall record and then points for and against and call it a day. One of the things we’ve learned in baseball is that there are statistics behind the scenes that are actually better predictors of player and team performance than pure game results. For instance, if a guy is hitting it hard, but hitting it right at people, he is likely to see an uptick in performance when he gets different batted ball luck. The same can be true of pitchers.
In our case, we are going to look at four different metrics to see how correlated they are with success and failure. We will divide the league into four quadrants and simply focus on the top eight teams and the bottom eight teams. The ones in the middle are often separated by a game or two and therefore the results are likely to be more random. First, let’s list our top eight and bottom eight teams according to record.
Top Eight: Green Bay Packers, Los Angeles Rams, Kansas City Chiefs, Tampa Bay Bucs, Dallas Cowboys, Tenneesee Titans, Arizona Cardinals, Buffalo Bills
Bottom Eight: Jacksonville Jaguars, Detroit Lions, Houston Texans, New York Jets, New York Giants, Carolina Panthers, Chicago Bears, Atlanta Falcons
What are the stats?
The statistics we will be looking at include turnover differential. If you ask any pundit, they will tell you that turnovers are the name of the game. This is likely both true and misleading. The question is how much does the turnover ratio correlate to winning and losing. Of course, we also don’t know if turnovers are generated consistently or avoided consistently. Further study would need to be done season to season on that question.
The second statistic is simply yards per game gained minus yards per game allowed. This would seem to be basic enough and yet it is likely related to the third statistic: time of possession. The more you hold the ball the less likely the opponent is to gain yards. So, one is likely correlated with the other and not necessarily significant on its own. Finally, we get the number of times you forced the team to punt minus the number of times your team had to punt.
I realize all three of these last stats are obviously related. The fewer times you punt the more likely you are gaining yardage and the more likely you are preventing the other team from gaining yardage. Obviously, the reverse is likely to be true. However, if that is the case then we should notice all three with strong correlations.
We could bust out the tables, but the results are probably easier understood if explained simply. Yards differential and punts differential were the strongest correlations with winning. In each case, five of the teams that finished amongst those top eight in wins also finished in the top eight in yards differential and punts differential. At first glance, that doesn’t seem impressive, but what is impressive is that every team that finished in the top eight in yards differential was a playoff team.
Baltimore was the only team to finish amongst the top eight in punts differential and not make the playoffs. Like many teams in the AFC, they were within one game of going. The correlation between having the worst differentials and losing was not quite as compelling, but six of the eight teams that finished amongst the eight worst records also were amongst the worst in yards differential. The correlation was almost perfect for punts differential as seven of the eight teams in the bottom of punts differential also had amongst the eight worst records in the league.
Time of possession and the turnover plus or minus were not nearly as correlated with winning and losing as yards differential and punts differential. Three teams finished in the top eight in turnover differential and failed to reach the playoffs. Houston was 11th in that category and was one of the worst teams in the league. Meanwhile a few playoff teams actually had negative turnover differentials (Tennessee, Las Vegas, San Francisco).
Time of possession wasn’t even worth the effort. Four of the teams that finished in the top eight in time of possession failed to make the playoffs. Bad teams were more likely to have their defenses on the field longer, but the ultimate goal here was to see which statistics actually have a stronger correlation with winning. Clearly, amongst these four statistics it was yards differential and punts differential.
If you’ve gotten this far you are probably waiting for the payoff. I don’t blame you. Below are the rankings for you Houston Texans in each category. Just as a warning, young children under the age of 18, sufferers of PTSD, and people with heart conditions should probably move along past this portion of the article.
Yards Differential: -106.3 (32nd)
Punt Differential: -30 (32nd)
Time of Possession: 28:14 (28th)
Turnover Differential: +3 (11th)
David Culley made good on his promise to focus on the football. Lovie Smith made good on his promise to focus on taking the football away. Baseball utilizes the Pythagorean record to look at how good teams really are. That doesn’t work well in a 17 game schedule. In short, we can often be fooled if we look at individual games. The team was 4-13 and probably should have beaten New England and Miami in the very least. Suddenly, a 6-11 season doesn’t look so bad.
This is where fans and executives can get trapped into magical thinking. Magical thinking occurs when both groups ignore positive luck and just focus on negative luck. “The Texans should have been 6-11 and they ended up getting nine draft picks and some better free agents. If a few of the undrafted free agents surprise us and if we get positive development from some of the younger players then maybe we could win 8 or 9 games.”
Any given Sunday is a thing. So, far be it from me to dash anyone’s hopes. Despite some calling Tim Kelly a top five play caller (looking at you Spencer Tillman) most sober people agree that’s nowhere near the truth. Maybe Pep Hamilton and his assistants scheme better and foster some improvement. Maybe a second season in Lovie Smith’s defensive system creates more cohesion and better overall performance. These things are all possible. However, the rankings above also indicate that this team has a lot further to go before they can hope to get anywhere near a .500 record.