Law of Diminishing Returns - a Blueprint for the Offseason

A fanpost from bevomav 2 days ago suggests a fascinating solution for the Cowboys in this offseason: instead of worrying about the defense, fix the offense. The core of his argument is as follows: The Dallas defense may have ranked a middling 16th in point per game allowed (21.7), it was a better performance than a few NFC playoff teams (the Giants, Packers, and Saints, in particular). Meanwhile, the Dallas offense only finished 11th in PPG scored (23.6), behind said same NFC foes. He reasons that in order to compete in the NFC, the Dallas offense is in need of a turbo boost. After the jump, a look at my how the law of diminishing marginal returns can help get the Cowboys back to the playoffs.

The first problem is using points produced or allowed as a measure of quality of either the offensive or the defensive unit. The reason is because the opposite unit has too much impact on the points allowed. Consider, as an extreme example, an impenetrable defense that causes 3-and-outs or a turnover every time they take the field. Wouldn't it be much easier for the offense to score points? Maybe all it would take is a 3-and-out of their own, but thanks to great field position, boom goes the field goal.

But I digress a bit. To most fans this year it seemed obvious that the offensive performance was a cut above that of the defense. The question is - which side of the ball to improve? Do we try to make a current strength even mightier, or devote resources to shore up the weak link? It's here we'll take a quick look at the law of diminishing marginal returns.


The law of diminishing marginal returns is an economic concept that states continuing to devote resources (inputs) to a production process will eventually yield a smaller return (outputs).

Consider the following gross simplification: 1 seed produced 10 fruits. A farmer, knowing this, may plant 100 seeds in a field and expect 1000 fruits come harvest time. (Take a moment and check my math. It's fine, I'll wait). However, the law of diminishing marginal returns states that as you plant more seeds, you will receive less and less in marginal return for each successive seed. The 1001st seed may, for example, only yield 90 fruits. The reason for this could be scarcity of nutrients in the soil, scarcity of labor in collecting the fruit, whatever. The point is that the more output a process is producing, the less efficiently you can continue to improve the process.

If the law of diminishing returns applies to football, we would expect it to be more efficient to improve a weaker unit than to improve a strong one. When I say more efficient, I mean that one input (in this case, a new player, coach, or scheme) will have a larger impact on the output (performance, league standing, whatever efficiency measure you'd like to use). In this case, I'm postulating that we could see a greater return on our investment by devoting our offseason to the defense.


The 2010 Houston Texans boasted a powerful offense led by Matt Schaub, stud WR Andre Johnson, and breakout RB Arian Foster. Unfortunately, they missed the playoffs because they also featured one of the worst pass defenses in NFL history. The 2010 Texans D finished in the bottom 3 of most major passing categories, whether counting stats or efficiency stats, ranging from passing TD's allowed to ANYA. The greatest ignominy might be their passer rating allowed, which was over 100. If you remember how badly Dallas played against the pass in 2010, consider that the Texans were appreciably worse.

You may know, if you've been reading ahead, that the Texans finished near the top of the league in all major categories on defense in 2011. How did they do it? Here are their first five draft picks:

All 5 on the defensive side of the ball. 2 pass rushers and 3 DB's. The Texans went all in on defense in the draft. But that's not all. They also signed Danieal Manning and Jonathan Joseph, the latter of which (in my opinion) was the best CB available last year. The results: A #1 ranking for their Wade Phillips-run defense.


It may be a bit much to look ahead to next season and think that with a few tweaks Dallas could be #1 in defense. But which is more likely - that a great offense could be pushed to otherworldly, or that a mediocre defense could, with a few tweaks, actually be a good one? Instead of trying to make the offense elite enough to clean up all the defense's mistakes, I say we just make the defense a little bit better.

Another user-created commentary provided by a BTB reader.