According to the Data: How to Value Quarterbacks in 2-QB Leagues

This article is part of our According to the Data series.

I've been discussing Value Based Drafting quite a bit recently, including in an article on visualizing VBD:

VBD is measured at Pro Football Reference as a player's points minus the points for a specific baseline player (No. 12 QB, No. 24 RB, No. 30 WR, and No. 12 TE, e.g.). Adrian Peterson's 2012 VBD, for example, is his fantasy points (307 in standard leagues) minus the points for the 24th-ranked running back - Danny Woodhead (117).

VBD is useful because it naturally captures scarcity. If the No. 24-ranked running back had scored 290 points last season, Adrian Peterson's adjusted VBD of just 17 would be miniscule. That small number represents the ability to find a comparable player later in the draft. All other things equal, we don't necessarily want the player who will score the most points, but the player who will score the most points relative to others at his position, i.e. the biggest outlier. That's why Rob Gronkowski has more value in the early rounds than Matthew Stafford, despite the fact that the quarterback will score more points.

In my first book Fantasy Football for Smart People: How to Dominate Your Draft, I advocate using the number of total starters in the league at a specific position as the baseline number. In a one-quarterback league, using the points scored by the No. 12-ranked quarterback from the prior season is a fine baseline.

But in leagues in which you're forced to start two quarterbacks, you need to refine your baseline because there's a major difference between starting the No. 24-ranked quarterback versus starting Aaron Rodgers. Last year's No. 24-ranked quarterback was Ryan Tannehill, whose 183 fantasy points were 163 fewer than No. 1 quarterback Drew Brees'.

Using the No. 24 quarterback as the new baseline, I re-charted 2012 VBD to account for two-quarterback leagues. The results are pretty awesome.

The VBD for the quarterbacks in two-quarterback leagues (orange) is almost a mirror image of that for the running backs (purple). The steep drop at the running back position was due to Peterson's outlier season, so we can pretty much throw it out. That means that the value of quarterbacks is effectively the same as their running back counterparts. But what does that look like? Pretty surprising. Check out the quarterbacks and running backs below, listed by ADP.

Note that I used the No. 24-ranked quarterback as my baseline to calculate VBD with the assumption of a 12-team league. If you participate in a 10-teamer, your baseline quarterback would be the No. 20-ranked passer. That's an important distinction; league size can greatly affect VBD. By altering your baseline player according to your league size, you'll naturally incorporate the potential scarcity of positions in the later rounds.

It's also worth noting it's generally easier to hit on late-round running backs than quarterbacks. The year-to-year consistency of quarterbacks trumps all other positions - we know Rodgers and Brees will be among the league-leaders by season's end - so you could make a case that quarterbacks are even more valuable than I've stated.

Finally, consider that you always need to implement a little game theory into your draft selections. Sam Bradford might have the same objective value as Ryan Mathews in a two-quarterback league, but if other owners are still overvaluing running backs, you shouldn't be drafting Bradford in the fifth round. There's always a delicate balance between obtaining "true" value and making optimal choices based on the perceptions of others, but it's important to understand quarterbacks are basically a mirror image of their running back counterparts in two-quarterback leagues.

Jonathan Bales is the author of the Fantasy Football for Smart People book series. He also runs the "Running the Numbers" blog at DallasCowboys.com and writes for the New York Times.