Cars, Drives, Points, and Eagles Time of Possession

Chip Kelly will most likely entertain questions about time of possession for as long as he chooses to believe it’s a meaningless statistic.  He’ll get annoyed by the questions.  He’ll be dismissive.  He’ll quip quickly while demonstrating a slight air of arrogance.  It’s just a matter of time before he responds with a "What the hell do you know?" and drops the mic.  And he might be right.  Even last year I wrote how time of possession is fool’s fodder.  But after giving it more thought, I’m starting to think otherwise.  Below represents my attempt to convince Chip that he (and I) may be wrong; that, in some sense, time of possession does matter.

I’ll start with this… Which of these cars can possibly drive 60 miles in the quickest amount of time?

Car A, which has driven 20 miles in 20 minutes

Car B, which has driven 30 miles in 30 minutes

Car C, which has driven 40 miles in 40 minutes

This isn’t a difficult question to answer, right?  You will most likely notice that each car is traveling at the same rate of speed, 60 miles/hour, and conclude that each will drive 60 miles in the same amount of time (60 minutes).

Similarly, which of these three teams can possibly score the most points in 30 minutes?

Team A, which averages 25 points in 25 minutes of possession

Team B, which averages 30 points in 30 minutes of possession

Team C, which averages 35 points in 35 minutes of possession

Like the question about the cars, you’ll notice that each team "drives" at the same rate of speed, one point per minute, so all three are relatively equal.  Each should score 30 points in 30 minutes.  If this is your conclusion, then you wouldn’t be wrong.

But there is another way to look at it, a way you should recognize every time you sit in your own car and push the pedal to the metal.  Cars don’t suddenly travel at 60 miles per hour.  They accelerate.  Through 20 miles, Car A accelerated at 180 miles per square hour while Car C accelerated at 90 miles per square hour.  If Car A’s acceleration was constant, and not its speed, then it could potentially drive 60 miles in approximately 35 minutes at an average speed approaching 104 miles per hour.  In contrast, given Car C’s acceleration, it could travel 60 miles in 48 minutes at an average speed approaching 74 miles per hour.  Car A would be the faster of the two.

Right now, the Philadelphia Eagles could be Car A/Team A.  They rank 31^st in the NFL in time of possession, sandwiched between two NFL juggernauts: the Jacksonville Jaguars and Oakland Raiders (not nice company), with Tampa Bay and Tennessee rounding out the bottom five.  The top five teams, on the other hand, are Indianapolis, Dallas, San Diego, San Francisco, and Detroit.

Despite the low time of possession ranking, the Eagles are the "fastest" (or most efficient) team in the NFL, averaging 1.17 points per minute (granted, a slew of defense and special teams touch downs contribute to that).  But the problem with points per minute is that it assumes that Team A is just as efficient as Team C.  This may not necessarily be the case.  What if a team that averages one point per minute and 25 minutes of possession actually possesses the ball for 35 minutes?  Would that team be on pace to score 35 points, or would its "acceleration" matter?

Team	Wins	Mins Per Game	Pts per Game	Pts/Minute	Pts/Square Minute
Philadelphia Eagles	5	26	30.5	1.1731	0.0451
Green Bay Packers	4	27	26.8	0.9938	0.0368
Denver Broncos	4	29	29.4	1.0138	0.0350
Atlanta Falcons	2	28	27.3	0.9762	0.0349
Cincinnati Bengals	3	28	26.8	0.9571	0.0342
Cleveland Browns	3	28	26.8	0.9571	0.0342
Seattle Seahawks	3	28	26.6	0.9500	0.0339
Baltimore Ravens	4	29	27.3	0.9425	0.0325
Miami Dolphins	2	28	24.0	0.8571	0.0306
New England Patriots	4	30	26.7	0.8889	0.0296
Tampa Bay Buccaneers	1	26	20.0	0.7692	0.0296
Carolina Panthers	3	29	23.5	0.8103	0.0279
Arizona Cardinals	4	29	23.2	0.8000	0.0276
New Orleans Saints	2	31	26.4	0.8516	0.0275
Kansas City Chiefs	2	30	23.8	0.7933	0.0264
Houston Texans	3	29	22.0	0.7586	0.0262
Washington Redskins	1	29	22.0	0.7586	0.0262
Oakland Raiders	0	25	15.8	0.6320	0.0253
Chicago Bears	3	31	23.8	0.7688	0.0248
New York Giants	3	30	22.2	0.7389	0.0246
Indianapolis Colts	4	36	31.5	0.8750	0.0243
Dallas Cowboys	5	34	27.5	0.8088	0.0238
Tennessee Titans	2	27	17.3	0.6420	0.0238
San Diego Chargers	5	34	27.3	0.8039	0.0236
Buffalo Bills	3	29	19.7	0.6782	0.0234
San Francisco 49ers	4	33	23.5	0.7121	0.0216
Minnesota Vikings	2	29	17.3	0.5977	0.0206
New York Jets	1	28	16.0	0.5714	0.0204
Pittsburgh Steelers	3	32	20.7	0.6458	0.0202
Jacksonville Jaguars	0	26	13.5	0.5192	0.0200
St. Louis Rams	1	32	20.2	0.6313	0.0197
Detroit Lions	4	33	19.3	0.5859	0.0178

Just like Car A, Team A has a higher rate of acceleration (.04 points per minute) than Team C (.029 points per minute).  This could mean that Team A has the potential to score more points than Team C if Team A possessed the ball longer.

For example, consider the Denver Broncos and Green Bay Packers.  Denver averages 29 points and 29 minutes of possession; Green Bay averages 27 points and 27 minutes of possession.  Using average "velocity", each team would project to 30 points per minute in 30 minutes of possession.  However, when using "acceleration", Green Bay holds a 1.7 point advantage if both teams possess the ball for 30 minutes.

	DEN	GB
Points/square minute	0.035	0.037
Points per 25 minutes	21.8	23.0
Points per 30 minutes	31.5	33.1
Points per 35 minutes	42.8	45.1

If we apply this logic to the Philadelphia Eagles and their next opponent, the Arizona Cardinals, you can see more vividly how possessing the ball more can increase point potential.

	PHI	ARI
Points per  minute squared	0.0451	0.0276
Points per 25 minutes	28.2	17.3
Points per 30 minutes	40.6	24.8
Points per 35 minutes	55.2	33.8

Using the Eagles’ current acceleration value (.0451 points per square minute) and assuming 25 minutes of ball possession, they have the potential to score 28 points.  However, if the Eagles possess the ball for 25 minutes, then the Cardinals possess the ball for 35 minutes, which could potentially yield them 34 points and a 6-point victory.  Yet if the Eagles possess the ball for just 5 more minutes, their point potential increases to 41 points, making them 2-touchdown favorites.

I’m using the phrase "possess the ball" deliberately.  Unlike the phrase "time of possession," it connotes a more active behavior, rather than a more passive, after-the-fact effect.  Chip Kelly and the Philadelphia Eagles can continue to minimize the impact "time of possession" has on the outcome of a game, but I bet Kelly still wants to possess the ball more often (by having his defense orchestrate more three-and-outs, for example).

After all, possessing the ball more often can lead to more f***ng points. And isn’t that the plan?

Note: Thanks to r/Eagles user spiderrico25 for pointing out that I mistakenly used velocity (60 mph) to calculate acceleration when I gave time and distance as known variables.  As a result, the acceleration values for each of the cars should be doubled.