Law of diminishing returns:
A concept in economics that if one factor of production (number of workers, for example, In Zeek's case carries) is increased while other factors (machines and workspace, for example, everything else on the team) are held constant, the output per unit of the variable factor will eventually diminish (YPC).
Law of diminishing returns is often used for the workplace, in some cases production of a factory. In this case the workplace would be the football field. And instead of workers while still producing more, but at a lesser rate, we have Zeek producing more, but at a lesser rate (YPC). And the other stuff you says has nothing to do with the law of diminishing returns as to how it pertains to Zeek, was to explain of why the cowboys would increase Zeek's carries, even if it results in less YPC, which mainly is that they don't care about Zeeks individual stats but their strategy to win the game. the more carries you have the YPC goes down but the yardages still goes up for example. Also other factors like slowing down the game could be in the game plan as to why you increase carries even though it negatively impacts YPC. Like I said: you saying that Zeek sucks because his YPC is not as high as some other backs, doesn't explain the whole story, neglects to mention other factors why zeek is getting more carries than other backs. Heck one of those factors being the very hallmarks of what power football is all about, the very philosophy behind slowing down a game by running the ball a lot.