Last November, I provided an updated version of my own draft value chart where I measured the value provided by each draft pick to his Approximate Value over the course of his first five years. A week later I decided another change was needed. While AV measures the value provided by a player, the marginal value provided by a player is a better measure of the value of a draft pick. As a result, I re-did the chart and only gave players credit for their AV above 2 points of AV.

You can view the values for both of those charts and the Jimmy Johnson chart here. This week, I spoke with Peter Keating of ESPN the Magazine, who is working on an article regarding how teams should value draft picks. Keating asked if I could make two changes to the chart, and I was happy to do so (and thought you guys might be interested). First, I increased the measure of replacement-level AV from 2 to 3 points. Theoretically, this change would reward the best players, as the higher the value used for replacement level, the fewer players that will meet that threshold. The other change was to reduce the number of years measured from five to four, since that matches the length of the typical rookie contract under the new CBA. The chart below shows the raw data and a smoothed curve depicting the marginal AV (over 3) produced by draft picks in the first four years of their career over a 28-year period.

As it turns out, the chart doesn’t really change even with these tweaks. In fact, if you chart the Jimmy Johnson draft chart, my second draft value chart from November (AV II in the graph below) and today’s iteration (AV III), the two AV lines almost perfectly overlap. Note: to plot all three draft value charts on the same graph, I divided the draft value for each pick by the draft value of the first overall pick for each of the three draft value charts.

The key takeaway isn’t how the two AV draft values compare to each other but how they differ from the Jimmy Johnson chart. The dropoff is much more severe in the Jimmy Johnson draft chart, which in my opinion, has arguably resulted in the exact opposite effect of what was intended. In theory, a standardized draft value chart that each team uses would make trading easier, since everyone would know the value of a draft pick. And in fact, many in the media still use the Jimmy Johnson draft chart (I do not know, but only assume (hope?) that no NFL teams actually use this chart). The problem is that the values associated with the Jimmy Johnson chart bear no relationship to reality. As a result, teams that want to trade down generally demand way too much from teams looking to trade up. It makes no sense to trade up based off of a chart that highly overvalues the top picks, so teams are very reluctant to do so. Conversely, because teams at the top of the draft don’t want to appear “taken” — i.e., by trading a top pick for less than what the media and fans think the top draft picks are worth — teams with high picks may be inflexible about what they will accept via trade.

This year will be an interesting test case, as most draftniks think the value at the top of the draft is very flat (i.e., the difference between the first and 20th picks is small). If that’s the case, then even my AV draft charts wildly overstate the value of the top picks, while the Jimmy Johnson chart would be essentially useless. Whether or not teams budge from the old values associated with top picks will be a fascinating side story to watch.

Finally, for Keating and everyone else out there, the table below shows the marginal draft values (over 3 points of AV) accumulated by the average draft pick for each slot over the first four years of the players’ careers: