There is a notion that rookie cornerbacks are still getting up to speed in the NFL, so they are therefore more vulnerable than veteran cornerbacks to being picked on by opposing passing offenses. We know that being targeted gives cornerbacks more scoring opportunities from a fantasy perspective, so it should logically follow that rookie cornerbacks would be some of the best fantasy options for Individual Defensive Player (IDP) managers.
Simple is sexy when it comes to advice. “I before E, except after C,” “sharing is caring,” and even “keep it simple, stupid” are all perfect examples of adages that help us quickly transmit information.
The same goes for fantasy football axioms: “Zero RB,” “late-round quarterback,” and “#NoTeamD.” The problem with these nuggets of wisdom, though, is that they only work if we don’t lose the nuance and context that helps apply that information usefully. The loss of context has happened in the IDP world when it comes to rookie cornerbacks. Here’s why.
Rookie Cornerbacks vs. Veteran Cornerbacks
A Cornerback in the Pros is Worth Two on the Bench
Tom Kislingbury, a good friend of mine and senior IDP writer at Dynasty League Football, took on the “Rookie Cornerback Effect” (referred to from here on out as the “RCE”) last year and posted some great work on Twitter to debunk the theory with data. In summary, his conclusion is that rookies don’t reach the top 12 or 24 thresholds at the fantasy cornerback position at nearly the rate that we would expect based on the RCE. In his thread, Tom largely points to snap counts as the reason why rookie cornerbacks do not trounce veteran cornerbacks in end-of-season rankings.
I was impressed, and all his work checks out on that front. The table below shows a comparison of the average fantasy cornerback’s production over the last five years, versus the average rookie fantasy cornerback in the same span of time (fantasy points are scored using the balanced scoring system with a 3:1 sack to tackle ratio).
|FF CB, 2015-19||Snaps||TKL||AST||FF||INT||PD||FPTS|
Tom is spot-on: the average cornerback plays more snaps, generates more production in every category (including tackles, assists, forced fumbles, interceptions, and passes defended), and earns more fantasy points than the average rookie cornerback. Another classic fantasy adage is that playing time – not skill level – correlates most highly to fantasy production; put another way, availability is the best ability.
Still, something is still missing from Tom’s analysis, as true and well-done as it is, and that’s actually what he uses as his argument against rookie cornerbacks: snap counts.
A Rookie Spent is a Rookie Wasted
Most of the time, we IDP analysts recommend you stream (pick up free agent players week-to-week based on matchups) at the cornerback position. With this strategy, we’re not concerned so much with season-long totals or end-of-year placement. On a weekly basis with cornerbacks, we want to find, in order:
- Who’s starting and playing a significant number of snaps,
- Who is being targeted the most often, and
- Who is reaping the benefit of those opportunities?
That means that if Tennessee Titans veteran cornerback Johnathan Joseph gets injured one week and is declared out, we don’t care that rookie cornerback Kristian Fulton is just filling in for the week. We don’t care that Fulton, as the Titans’ fourth cornerback, likely won’t have a high-enough snap total to make the top tier at the position by the end of the season. Frankly, we don’t even care that he’s a second-rounder fresh out of the NFL draft filling in for a former Houston Texans’ star who ranks fourth among active NFL players in career interceptions and is potentially on his way to the Hall of Fame.
We simply ask ourselves: is Fulton – or any cornerback – playing in a big role this week? If so, he fits the bill for exploiting the RCE.
The next piece of the puzzle is to determine who is being targeted the most often.
If we just use raw totals, over the last five years, the average veteran cornerback was targeted 41.2 times in a season; the average rookie cornerback was targeted 28.9 times over that same span. Once we integrate snap counts, however, we begin to see a slightly different picture.
Now, instead of raw totals that are influenced by playing time, we see that the average cornerback is targeted on 14.7 percent of their coverage snaps, while the average rookie is targeted on 15.3 percent of theirs. While not a significant difference to say that rookie cornerbacks are better fantasy options, this swings the pendulum the other way from the picture when just looking at totals.
In fact, this leads directly into the final point of our fantasy cornerback checklist: when adjusting for snaps played, every fantasy category rate begins to favor rookie cornerbacks slightly. The table below shows this for the traditional scoring stats for both veteran cornerbacks and rookies on a per-snap basis.
|TKL %||AST %||FF %||INT %||PD %||FPTS per Snap|
When streaming cornerbacks, isolating one-week performances as we should be with this position in IDP fantasy football (even in dynasty leagues), you can maximize the value of the RCE. When a rookie is thrust into a starting role, there’s a decent chance for you to get an 8.5 percent increase in fantasy scoring from that position for the week. Sure, it’s a small advantage, but we should look for every edge we can find in the ever-more-efficient fantasy football world. Rookie cornerbacks do provide a slight edge, in small doses.
Better Drafted Late than Ever
So, practically, how do we best use this information? We don’t.
It sounds cryptic, but that simply means you still shouldn’t draft rookie cornerbacks any higher than you normally would in your dynasty league startup or free agent drafts (which should be late or not at all, since you should be streaming them weekly). You shouldn’t draft them earlier than you have to with rookie draft picks, since there are still relatively few that earn high snap totals across a season, and that’s a waste of draft capital.
Instead, you should mainly be using your free agent bids as chances to snap up an interesting and vulnerable rookie cornerback when they get the starting nod in a week and make sure they aren’t one of those lockdown rookie phenoms who aren’t getting targeted (PlayerProfiler.com’s depth charts are a great place to get target rate and snap info). Let your league-mates waste valuable draft picks on rookie corners who won’t start early on, then once they drop them, go ahead and churn through them as the season continues and they get starting opportunities.
Sure, this process isn’t as sexy as something called “Zero Rookie CB,” but the RCE is real and can be exploited – if you take the time to learn its nuance.