How much correlation is there between quarterback play and team wins in 2014 so far?

While the CFL's teams can be easily classified by how stable their quarterback situation is, that doesn't explain the entirety of their different records to date. Some teams with proven starters at quarterback, such as Toronto and Ottawa, have still struggled; the Argonauts and Redblacks are 3-5 and 1-6 respectively heading into Week Nine. Meanwhile, there may not be quarterback questions in Calgary or Edmonton, but the pivots there aren't setting the league on fire from a statistical perspective. The Stampeders and Eskimos are both 6-1 despite that, though. How important is consistent production from the quarterback position? Here's a table showing each team's passing yards per game so far and their record:

And here's that data as a scatter plot:

Note the lack of correlation; many of the league's best passing teams by this mark aren't winning many games, and the league's best teams by record aren't throwing for many yards per game. Of course, there are some factors that affect this, and passing yardage isn't a perfect metric. Teams that fall behind early tend to throw more, but they also tend to lose more. What about if we look at average gain per pass per pass and completion percentage? Here's a table with that:

Here's winning percentage against yards per pass as a scatter plot:

This looks slightly less random than the average passing yards one, but not much. There's still next to no relationship between the two variables, and what relationship there is is largely from Montreal being terrible in both categories; the rest of the teams don't align well. What about by completion percentage?

That's slightly better still, but there's still next to no correlation. That's not to say that completion percentage, gain per pass or passing yards per game are irrelevant; they all obviously matter, to an extent, and it's notable that the Alouettes are awful at all of them. It's more that some teams with passing games that are mediocre to lousy in at least one of those three areas (particularly Edmonton and Saskatchewan) are still doing well, while some teams with good to great passing games (namely Toronto and Ottawa) aren't translating that into wins; that suggests they have other issues, such as consistentcy in the rushing game and on defence. Thus, having a good quarterback situation doesn't mean you're going to set this league on fire. It does mean that you can focus on improving other areas of the team, though. Moreover, having a bad quarterback situation isn't going to work out at all. Quarterbacks do matter to winning, perhaps more than any other player on the team. That doesn't mean they should be judged by wins and losses, though; as this data shows, there's much more to a team's record than just quarterback play.