The Cowboys have invested 22 draft picks into defensive backs since 2005. Outside of the three first-round picks Mike Jenkins, Morris Claiborne, and Byron Jones, only two of the remaining 19 picks, Orlando Scandrick (fifth round, 2008) and J.J. Wilcox (third round, 2013), worked out somewhat favorably for the Cowboys.

A "hit rate" of two out of 19 raises questions about the Cowboys' scouts ability to recognize what makes an NFL-caliber defensive back. And this is especially worrisome as there's a good possibility the Cowboys could draft another cornerback or two next year.

One thing that stood out when we looked at the leaked 2016 Cowboys draft board yesterday was that there were a lot of cornerbacks that were picked at least a round above where the Cowboys had graded them. Here's how the Cowboys graded the cornerbacks on their draft board relative to where those players were actually picked in the 2016 draft.

Cornerbacks on 2016 Cowboys draft board Round Pick Team Player POS Cowboys Grade Difference 1 5 JAC Jalen Ramsey CB 1 0 1 10 NYG Eli Apple CB 1 0 1 11 TB Vernon Hargreaves CB 1 0 1 24 CIN William Jackson III CB 3 -2 1 25 PIT Artie Burns CB 2 -1 2 38 MIA Xavien Howard CB 3 -1 2 54 MIN Mackensie Alexander CB 3 -1 2 58 PIT Sean Davis CB 5 -3 2 60 NE Cyrus Jones CB 4 -2 2 62 CAR James Bradberry CB 4 -2 3 74 KC KeiVarae Russell CB 4 -1 3 77 CAR Daryl Worley CB 5 -2 3 84 WAS Kendall Fuller CB 2 1 3 92 ARI Brandon Williams CB 5 -2 5 157 TEN LeShaun Sims CB 4 1 6 189 DAL Anthony Brown CB 4 2

What you can see here is that the Cowboys got the grades for the top three picks right. However, that in itself is not a major achievement - most draftniks had those three guys going in the first round.

Where it gets really worrying is after those top three. Of the 13 players with a second- to seventh-round grade, ten (77%) are graded lower than where they ended up being picked. What this means is that if the Cowboys were following their board and weren't going to "reach" for a prospect beyond round one, there were just two cornerbacks they could have drafted. Kendall Fuller had a second-round grade and was still available when the Cowboys picked in the third (though injury concerns may have dropped him lower, and after drafting Jaylon Smith, the Cowboys' tolerance reserves for injured players was probably depleted). Anthony Brown was still available in the sixth, had a fourth-round grade, and the Cowboys ended up picking him.

In 2010, a group of industrious BTB bloggers painstakingly decoded a video shot in the Cowboys draft room that showed the Cowboys draft board. In 2013, our own rabblerousr decoded the 2013 draft board. Add the 2016 draft board and we now have three draft boards to look at, and what we can see is not pretty for cornerbacks.

In 2010, 67% (8 of 12) of the CB prospects without a first-round grade were graded at least one round lower than where they were eventually picked. In 2013, that number decreased slightly to 60% (9 of 15) before jumping back up to 77% (10 of 13) this year. In total, that's 68% (27 of 40) of prospects without a first-round grade who were graded lower than where they were drafted. That's not a coincidence. That's a systemic issue.

The Cowboys' draft grades may be correct in terms of player quality/potential and fit with the Cowboys - or they may be incorrect, I'm in no position to judge. But that doesn't matter one bit. If you're grading 66% of the players (outside of first-rounders) below where they'll get picked, the likelihood of getting a cornerback by sticking to your draft board is pretty slim.

In economic terms, what we have here feels like a seller's market: In a seller's market there are more buyers than sellers, and high prices result from demand outstripping supply. Translated to the NFL, this means that there are not enough corners to meet the demand of NFL teams. As a result, you likely have to overpay in terms of draft picks to get one.

Quality corners are a scarce commodity. Other teams appear to be 'paying' for their corners with higher draft picks, and the Cowboys may have to do the same if they want to upgrade their secondary next year. We now have three draft boards to go against, and the history of the Cowboys drafts suggests that the 'mis-grading' of cornerback talent is a persistent issue for the Cowboys.

For all I know, the Cowboys' draft grades may be right. But if demand outstrips supply, you've got to accept that you'll have to pay a premium for a quality corner and you may have to factor that into your draft board. Otherwise you run the very real risk of wasting yet another draft pick on a corner who won't pan out and who you'll have to replace with an expensive free agent.

It's important to understand that undervaluing or undergrading per se is not really an issue, as long as you then take the market environment into account and recognize that other teams are either grading higher or willing to spend more. So if you really need a corner, you may have to accept that the guy with the third-round grade on your draft board will not be there in the third round anymore, and you'll have to pick him in the second round if you really want him.

We'll continue our look at the Cowboys draft board over the next few days, and in our next installment we'll look at the other position groups that may be over- or undergraded. Because the 68% 'undergraded' rate for CBs (outside of first-rounders) is only the second-highest among all Cowboys position groups across the three draft boards. But which position group do you think will come out on top?