In my inaugural post, I promised that I would post an updated draft value chart prior to the draft. Since the draft starts tomorrow night, I realized that I couldn’t procrastinate any longer so here you go!
My initial draft chart was based on Chase Stuart’s draft value chart using Approximate Value (“AV”), a statistic that approximates the value (hence the name) of all past and present NFL players in order to compare players of different eras and different positions. Since we know the value of each player over time at each position, we can use that to value each selection in the draft.
There were two major differences in my draft value chart and Chase’s:
- Unlike Chase, I looked at draft results from 2002 to 2012, which is more recent (but not as long) than Chase’s time period of 1980 to 2007. I explain why I used this time period in my initial post.
- I summed the weighted average ‘career’ AV for the first four years for all players drafted in the second round and later and the first five years for first round picks. Since teams have the option to extend first round picks’ contract to a fifth year, first round picks are more valuable relative to players chosen in later rounds.
In addition to these differences, I’ve made two additional modifications in this round:
- I removed all kickers and punters from the calculation. The approximate value calculation values kickers and punters differently than offensive and defensive position players. Pro-Football Reference goes into detail on how approximate value is calculated for kickers and punters but, to keep it short, AV for a kicker and punter is not comparable to AV for a player of a different position, all else equal.
- In my first draft value chart, the last eight picks (246 through 253) were negative. That doesn’t make any sense. No picks should have a negative expected value. To fix this, I shifted the curve up by the absolute value of the 254th. There are 253 selections in the 2017 NFL draft (224 picks+ 33 compensatory picks – 4 forfeited picks for being naughty) so this shift leaves the 254th pick with an expected value of zero and a positive expected value for #1 through #253.
These are minor corrections. They fix small issues, improve the reliability of the chart, and enhance its conceptual value. With these changes, below is the updated draft value chart:
To understand this data, I’ve included the updated chart compared to the Jimmy Johnson chart and Chase Stuart’s chart. The Jimmy Johnson chart has been scaled down to values proportional to the Chase Stuart chart to put it in terms of AV for comparison.
The difference between my chart and Chase Stuart’s chart is negligible and not apparent from this chart. There are, however, large differences between these charts in sixth and seventh round picks. For example, pick #224 on my chart is worth 0.79 of AV compared to 0.1 of AV per Chase. While this is a small difference in terms of overall value, this means that I value this pick eight times more than Chase does.
In contrast, there is a large difference between my chart and the Jimmy Johnson chart. As I have discussed before, the Jimmy Johnson chart overvalues early picks considerably. But it also undervalues mid-round selections. If teams use the Jimmy Johnson chart to value picks, it would significantly affect their draft strategy. It tells teams to trade up early picks at the expense of their mid-round picks. Teams that stray away from the Jimmy Johnson chart and use an updated chart (like mine!) have a competitive advantage by exploiting a market inefficiency. So when teams make trades during the draft the next few days, feel free to use my chart to analyze the trade.
Rookie Wage Scale
As I was thinking about some of the changes to make to my draft value chart, I thought about adjusting the distribution of AV by position based on current salaries. The idea behind this was that the distribution of salary by position would better represent the value of each position relative to other positions. When I made these adjustments, it didn’t improve the chart so I disregarded them and didn’t include them.
However, it did lead me to ponder how rookie wages are distributed by pick compared to the draft value chart. That is, how does the rookie salary at each pick compare to the expected approximate value at that respective pick? To answer this, I compiled the expected 2017 rookie salary for each draft pick in the upcoming draft via overthecap.com. My draft value chart and the rookie salaries, proportioned to the draft value chart, are shown in the figure below.
What does this show? Wherever the rookie wage line (the yellow line) is above the draft value chart line (the red line, which represents AV or expected output), the player taken with that pick is receiving a salary above expected output. This also means that wherever the rookie wage for a certain pick is below the expected AV for that pick, the player will be undercompensated, relative to expected output. Even with the structured wage scale ending exorbitant salaries to early first round picks (Sam Bradford was lucky to be the last), the first 10 picks receive a salary above their expected output.
#11 through #128 (the last pick of the fourth round) receive a lower salary than their expected output. For those feeling sorry for these guys, don’t worry, the 128th pick will still receive a $613,304 base salary before signing bonus, which is more than I’ll make in a long time.
Overall, if someone has a connection with the NFL, they might want to tell them to reset the structure of the rookie wage scale. If I’m a mid-round pick, I’d be bitter about my compensation even before I enter the NFL.