The Rookie Effect (Updated for 2021)

I once saw a sign; the type that a mother would hang in the guest bathroom as a talking piece, that read “By the time a man realizes his father was right, he has a son who thinks he’s wrong”. I chuckled for a second, snapped a pic, and sent it to my dad. A very proverbial way to describe the circle of life. We enter, we stay awhile, and then we leave. “C’est la vie”, as the french would say.

My wife, having given birth to our first son last year, has shaped the fantasy offseason slightly differently within the walls of my own mind. I’m still just as active in my leagues, I still harass my league mates with trade offers, and I even entered the fantasy football twitter community. What’s new this year is, I’ve become disgustingly aware of the fact that most of the NFL player population is younger than me. This fact has shifted my focus this year to incoming rookies. 

Just like the father and son pass along wisdom, albeit too late, in the sign I saw, the veterans of the NFL pass along their knowledge to the incoming stars. However, along with their knowledge, they pass along their snap share, and eventually their jobs. This got me thinking, how do incoming rookies affect their team? How will Ja’marr Chase affect his new teammates? Will Trevor Lawrence help the WRs for whichever team he lands on? I dove into the recent rookie numbers and here’s what the research uncovered.

First, I wanted to ensure that I wasn’t blindy targeting rookies that were drafted and had no impact on the team. I wanted to filter the criteria of rookies in which their team had spent significant capital on them: 1st and 2nd round QBs and WRs, and include 3rd round for RBs. Then I tried to make sure that each rookie dressed for 10 games and contributed “enough” for me to say that they had an impact. Then I compiled positional fantasy scores for the offensive positions for both the year before the rookie was injected into the offense and their rookie campaign. 

Quarterbacks

Rookie QBs take some time to adjust to the NFL. Although there were some significant outliers, rookie QBs on average reduced the offensive production of the other skill positions. The point differential and % of seasons where the outcome was positive (the position scored more points in the rookie’s year than the previous year) are as follows:
RB1: -9.7 points and a 34.6% positive rate

WR1: -18.3 points and a 30.8% positive rate

WR2: -0.92 points and a 50% positive rate

TE1: -6.6 points and a 46.2% positive rate

Now, these numbers don’t seem too drastic. However, coupled with the rate of negative chance I think that it’s safe to say that skilled position players will likely take a hit, in terms of fantasy production, if their offense is helmed by a rookie.

Removing the top 2 and bottom 2 outliers for the QBs had virtually no effect. Yet, breaking up the 1st round and 2nd rounders did:

	RB1	WR1	WR2	TE1
1st Round Diff	-1.48	-11.62	-0.04	-4.88
1st Round Pos %	37.5%	29.1%	54.2%	41.7%
2nd Round Diff	-41.9	-45.2	-4.4	-13.6
2nd Round Pos %	16.7%	33.3%	28.6%	50%

Essentially, what we can take from this is: 1st Rounder QBs tend to have a better effect on their teams than 2nd Rounders, but you should harness expectations for players playing with an high draft capital rookie QB.

Running Backs

This position was a little more interesting to me, since rookie RBs tend to be a bit more useful in fantasy than rookie QBs. From a numbers standpoint 1-3 round rookie RBs, when implemented into an offense over the last 6 years had a much more positive effect on their skilled position teammates fantasy outcome than QBs. Here’s the break down:

QB1: +28.1 points and a 54.8% positive rate

WR1: +22.6 points and a 54.8% positive rate

WR2: -11 points and a 38.1% positive rate

TE1: -7 points and a 45.2% positive rate

What stands out here is that spending a top 3 round draft pick and adding a rookie RB to an offense, tends to help out the QB AND WR1 for that team. Not only that but at a >50% rate. Applying this to the new draft class would suggest that Harris, Etiene, etc will increase the production of their new teammates, assuming they go in the first 3  rounds.

I then again broke up the numbers by round. Most of the numbers remained true however here are some points I found interesting:
 

• 3rd Rounders increased QB production by 36 points (about the same as a 1st rounder)
• 3rd Rounders increased the WR1 production 70.6% of the time
• 1st Rounders decreased the TE production by 51 points
• 1st Rounders decreased the TE production 87.28% of the time
• RBs drafted in the first round have increased the production of their respective WR1s by an average of 22 pts and at a 57% rate

The first two points are pretty on par with the total averages, however the 1st round effect on TEs is something to consider. Could this be due to a team keeping the TE as an extra blocker in order to get the rookie they spent so much draft capital on some volume? Could this be because 1st rounders are on the field more than 2nd or 3rd rounders and RBs tend to pick up the pass blocking game slowly? 

Wide Receivers

Last but not least are the Wide Receivers. For this group I decided to factor in another metric: I tracked how frequently a rookie took over as the teams WR1 or WR2. Also, if they did take over, were they more or less productive than the WR1 or WR2 the previous year.

First, let’s take a look at the averages. The point differential and positive rate are as follows:

QB1: +18.9 points and a 64.2% positive rate

RB1: +7.3 points and a 59% positive rate

WR1: -2.86 points and a 49.1% positive rate

WR2: +22.2 points and a 64.2% positive rate

TE1: -2.8 points and a 47.2% positive rate

So, over the last 5 years, adding a rookie WR in the first two rounds of the draft bodes well for fantasy production. Breaking it up by round provided the following points:

	QB1	RB1	WR1	WR2	TE1
1st Round Diff	1.1	15.5	9.26	17.1	-8.6
1st Round Pos %	52.2%	60.9%	60.9%	52.2%	47.8%
2nd Round Diff	32.46	1.1	-12.2	26.1	1.7
2nd Round Pos %	73.3%	56.7%	50%	70%	46.7%

There are some very apparent differences here. Note the rate at which Rd 2 WRs positively impacted both QB1 and WR2. 

Lastly, the idea of how frequently a rookie WR “took over” the role of a teams WR1 or WR2 piqued my curiosity. Here’s how it broke out:

WR1	# of Takeovers		13	WR2	# of Takeovers		15
	% of Takeovers		24.07%		% of Takeovers		27.78%
	# of Takeovers Better than Prev		8		# of Takeovers Better than Prev		10
	% of Takeovers Better than Prev		61.54%		% of Takeovers Better than Prev		66.67%

Of 53 qualifying rookie WRs drafted in the 1st and 2nd rounds, 28 (52.8%) of them took over in their rookie year as AT LEAST the WR2. Let’s dig deeper: 

• 14 of the 28 (50%) were selected in the 1st round
• 8 of those 14 became the top scoring WR for their teams in their rookie season
• 6 of those 8 scored more than the WR1 the previous year.

How to Apply the Data

All of the numbers presented above had significant outliers on both ends of the spectrum. Am I saying that Jacksonville skill players are untouchable in drafts this year due to a potential rookie QB? No. These are just correlations that you can apply to adjust variance windows.

The point is: a new generation of players enter the league every season. Some are very good, some aren’t. However, if a team spends significant draft capital on a player then they will do everything in their power to ensure that the new generation succeeds. Even if it means making sacrifices.