By Mark Simon and Alex Vigderman

Last week we wrote about how messy The World’s No. 1 QB Rankings got once you got past the top three quarterbacks.

This past weekend proved our point. Patrick Mahomes and Aaron Rodgers each had above-average Points Above Average (PAA) in their respective games. Of the next six quarterbacks, four had below-average numbers and the other two (Tom Brady, Drew Brees) didn’t play.

The World’s No. 1 Quarterback Ranking is based on a model devised by Bill James to evaluate The World’s No. 1 Starting Pitcher. Bill’s model was based on cumulative evaluation of individual starts over an extended time period using the metric Game Score.

The World’s No. 1 Quarterback Ranking uses our player value stat, Total Points to make a cumulative evaluation of game performance over a three-year period. The key to our calculation is Points Above Average, the statistical underpinning of Total Points that is centered at zero so that positive numbers are above average and negative numbers are below average.

Success over time is key to maintaining a good ranking. Prolonged inactivity results in a ranking drop. The recent performances carry the most weight.

Tannehill and Mayfield move up

So let’s talk about something other than the top of the list, shall we? Let’s touch on the two quarterbacks who had the best games of Week 13. Coincidentally, they were going head-to-head.

Titans quarterback Ryan Tannehill moved up three spots from No. 13 to No. 10 after throwing for 389 yards in a losing effort against the Browns. This is the first time that Tannehill has been positioned this high in the rankings in the three seasons for which we have data.

Tannehill looked like someone who was going to be a Top 10 quarterback in Weeks 5 and 6, but then slipped, totaling -4 Points Above Average in his next six games. Despite that, over that span he still moved up a spot in the rankings, which speaks to the parity of quarterbacks once you get past the top few.

But the big mover in the game was Browns quarterback Baker Mayfield, who went from No. 22 to No. 15. Mayfield, who was ranked No. 26 two weeks ago, has had two straight huge games against the Jaguars and Titans, respectively. Mayfield had a 93.5% on-target percentage against the Titans, the fourth-highest percentage for any quarterback with at least 20 pass attempts in a game this season.

This week’s most notable dropper was Justin Herbert, who had made a nice steady climb to No. 12 in recording eight games with a positive Points Above Average in his first ten appearances. But Sunday, Herbert had the worst game of any QB this week and the fifth-worst of any QB this season against the Patriots. (-17.6 Points Above Average). This is an easy one to evaluate on the surface. Herbert’s 53 pass attempts were the most of any quarterback with a completion percentage below 50% this season. He also didn’t help matters with two interceptions and three sacks.

In this World’s No. 1 QB system, a QB with limited experience can’t take that kind of hit without suffering significant damage to his statistical ledger. In Herbert’s case, that drops him to No. 21.

Here are the updated rankings.