When the Eagles' Nick Foles and the Patriots' Tom Brady take the field as the starting quarterbacks at U.S. Bank Stadium on Sunday, they will represent one of the most lopsided QB matchups in the 52-year history of the Super Bowl. But it's probably not close to being the worst pairing ever.

So which one is? We could compile a list of what we think are the worst matchups and then ask you to vote (which we'll also do; just scroll down), but that approach would be tainted by our and your biases. How do we remove that bias from the equation?

The question is whether there is a way to statistically measure the gap that exists between Brady — who is in the 17th season of the most accomplished, and likely best, quarterback career in the history of football — and Foles — who has never been a starter for a whole season in six years of pro football and has been on three teams the last three years — and compare that gap to the previous 51 quarterback pairings in the Super Bowl.

There is no modern-day catchall statistic for measuring football performance like baseball's wins above replacement or basketball's win shares. Football Outsiders has a metric called DYAR, defense-adjusted yards above replacement, to measure QBs, but the results go back to only 1986, leaving the first 20 Super Bowls out of the mix. ESPN's total QBR statistic goes back to only 2006. Using those numbers would exclude a matchup many would predict to be one of the worst ever.

That leaves us with the NFL's passer rating. It was adopted by the league in 1973, but because it's calculated using a player's common statistics — completions, attempts, yards, touchdown passes, and interceptions — passer rating is available going back before the Super Bowl era. It's far from a perfect statistic, especially when applied to small samples. (It's unlikely Falcons receiver Mohamed Sanu, with his perfect 158.3 passer rating from one pass, was the best quarterback in the NFL this season.) But the larger sample we take, the better picture passer rating provides. And if we use that number and consider factors such as usage, experience, and performance that season, we can rate the pairings.

We crunched the numbers, and those ratings say Brady vs. Foles is the second-biggest mismatch at quarterback in the history of the Super Bowl. The biggest, however — Terry Bradshaw vs. Vince Ferragamo in Super Bowl XIV — was much larger.

### The method

We can't simply compare passer rating numbers, however. It's a rate statistic that doesn't consider volume. There are other factors fans and pundits typically consider when comparing quarterbacks, particularly experience and usage.

If you stack up two quarterbacks with similar ratings against each other, the more-veteran player is typically considered more valuable. And a quarterback who has thrown more passes is usually thought to be more important to his team's offensive performance.

So, to use passer rating as a proper tool, the number needs to be weighted for those factors. For each Super Bowl, we multiplied the career regular-season passer rating before the game (because we want to know what the general feeling was that day) for both starting quarterbacks by games played and pass attempts. By comparing those numbers for each quarterback, we can compute a percentage difference, then average those results to give us an index to compare to other games.

Of course, the single season a quarterback is having going into the game is a consideration, too. We can create a number based on the same formulas for a single season, and then put that into the mix, too. The question then is, how much consideration is given to career vs. season? We produced three sets of results based on a single season being worth 40 percent of the index, half of the index, or 60 percent of the index.

How does it all come together? Let's look at Super Bowl XV as an example. To that point in his career, the Eagles' Ron Jaworski had a career 72.3 passer rating over 1,693 pass attempts in 86 regular-season games. The Raiders' Jim Plunkett had a 62.1 rating, with 2,329 attempts in 104 games. That season, 1980, Jaworski had a 91.0 rating over 16 regular-season games with 451 attempts, compared to Plunkett's 72.9, 13, and 320. Here are the calculations:

• Plunkett's career rating multiplied by his attempts is 144,630.9, 18.16 percent better than Jaworski's 122,403.9. When rating is multiplied by games, Plunkett's 6,458.4 is 3.87 percent better than Jaworski's 6,217.8. The average of 18.16 and 3.87 is 11.02.
• The script flips when considering their performance in 1980. Jaworski's season rating multiplied by attempts (41,041) is 75.93 percent better than Plunkett's (23,328). When multiplied by games, Jaworski (1,456) is 53.64 percent better than Plunkett (947.7). The average of 75.93 and 53.64 is 64.79.
• We can take Jaworski's 64.79 season advantage and subtract it from Plunkett's 11.02 career advantage and then divide it in half to average the two numbers (and divide by 10 to make the numbers more pleasing to the eye) to get a score of 2.69. We'll call this the advantage index. If we weigh those numbers so the season is worth 40 percent of the score, the advantage index is 1.93 in Jaworski's favor. If the season is worth 60 percent, the index is 3.45.

The Jaworski-Plunkett matchup is one of the closest in Super Bowl history, by our measurement.

### The results

The Bradshaw-Ferragamo matchup in January 1980, which the Steelers won, 31-19, is by far the "winner." If you consider a player's career is worth 60 percent of the score and the lead-in season 40 percent, the gap between Bradshaw and Ferragamo is more than twice as large as the one between Brady and Foles.

### Super Bowl QB Mismatches (first scenario)

Here are the biggest Super Bowl quarterback mismatches ever, ranked by our advantage index. The index uses the NFL’s passer rating statistic and weighs it for experience and usage. In this scenario, the player’s career is worth 60 percent of the index, and the lead-in season is worth 40 percent. The “better” quarterback is listed first. For reference, the mismatch gap between a pairing with an index of 50 would be 50 times greater than a pairing with an index of 1.
T.J. FURMAN / Staff

There are a lot of similarities between the Super Bowl XIV quarterback pairing and the one coming up on Sunday. Bradshaw was in the 10th season of a Hall of Fame career, and Ferragamo was in his third season and had started only five games in his career — all in 1979. His career passer rating of 51.4 going into the game is the worst ever for a Super Bowl starting quarterback.

When we adjust the career-season balance to an even split, the top two spots remain the same, with Bradshaw-Ferragamo still having a gap more than twice that of Brady-Foles.

### Super Bowl QB Mismatches (second scenario)

In this scenario, all of the calculations are the same, except the player’s career and season performances are worth the same amount in the final advantage index.
T.J. FURMAN / Staff

If we adjust the balance so the lead-in season is worth 60 percent of the advantage index and a career is worth 40 percent, the top two remain the same, but the difference is not as great. In that case, the Super Bowl XIV mismatch is only 1.9 times as big as the Super Bowl LII gap.

### Super Bowl QB Mismatches (third scenario)

In this scenario, the player’s season is worth 60 percent of the advantage index, and his career contributes 40 percent to the score.
T.J. FURMAN / Staff

Finally, to get a composite of the three, we can apply a ranking to each matchup in the three scenarios (52 for the biggest mismatch, 1 for the smallest), and then average those rankings.

### Average QB-Mismatch Rank

An average of the rankings from the three scenarios above. While this provides an average ranking, it does not show the disparity between the worst mismatch and the others in the list.
T.J. FURMAN / Staff

A few notes about the three scenarios:

• The top five remains the same in all three equations.
• While Bradshaw-Ferragamo is clearly outpacing the field, the Foles-Brady matchup is in a tight grouping, so it might be fairer to say it's in a tier of mismatches that could be considered the second-worst, along with Jim Kelly vs. Jeff Hostetler (XXV), and Peyton Manning's games vs. Russell Wilson (XLVIII) and Rex Grossman (XLI).
• The only matchup that flips from one quarterback to another is Steve McNair vs. Kurt Warner in Super Bowl XXXIV. In the 60-percent-career and even-split tables, McNair is the better quarterback. When the season is worth 60 percent of the index, Warner's MVP season makes him the better player.