EXAMPLE 13 Does Running Lead to Winning in Football?

A football broadcaster discussed how often a team wins when it runs the ball at least 30 times in a game. For the 2010 NFL regular season, the correlation between wins and number of running plays was indeed close to being moderately positive (). Could this mean that running causes winning—that all any team has to do to win more games is to run the ball more? No. In the extreme, if a team executed only running plays, the other team would simply adjust its defense to focus on and stop the run. Basically, once teams get a good lead in a game (regardless of their mix of special teams, running, and passing), they tend to start running the ball more often as a way to minimize the risk of losing the ball (pass plays are riskier) and to use up the clock faster (an incomplete pass stops the clock). And when teams fall far behind late in the game, they begin passing more often as a last chance to catch up before time runs out.