After a brutal injury, a quarterback controversy, and a less worrisome injury, we'll examine the differences of Ryan Tannehill and Matt Moore, Dak Prescott and Tony Romo, and Matt Stafford and Dan Orlovsky. To do so, we'll simulate each remaining game 50,000 times for each quarterback on their respective teams.
Matt Moore isn't as big of a step down from Tannehill than one would expect. Moore is one of the better backups in the league, statistically speaking. This also assumes Tannehill's season thus far isn't a career-changing moment as we should all expect him to regress to his career numbers, in some regard, until we have a larger sample of career-high play.
The Prescott-Romo saga doesn't seem to be the story the media wants it to be. Jerry Jones and Jason Garret made it clear Romo would not be replacing Dak Prescott. Our simulation doesn't provide a clear answer for them, either. Romo does have the advantage of being 0.8 points per game better than Prescott. Romo is the better passer, especially in downfield situations. However, Prescott's ability to avoid turnovers gives him an advantage to close the gap on accuracy and downfield passes. We should also note that this assumes there would be no rust on Romo's game, which would be a tough assumption to make.
Matt Stafford seems to be fine but he'll be playing less than 100% for the rest of the season. In the hypothetical situation that Stafford does not turn out to be able to play, Dan Orlovsky would fill that spot. Orlovsky is quite a step down. Not only is Stafford having his career year, Orlovsky is one of the worst backups and has very little game experience over the last few years. Stafford didn't look great on Sunday against the Bears, but it would be a hard case to make that he's nearly five points per game worse, the difference between him and Orlovsky, with his injury.