If you tune into the occasional Rick Spielman press conference like I do, you've probably heard him state the Vikings' team-building strategy: build through the draft, and supplement with free agency. Due to the massive success of the 2017 Philadelphia Eagles, NFL teams are beginning to question this approach. Teams with quarterbacks on rookie deals have been dishing out massive free agent deals or trading high draft picks for proven talent throughout the offseason. The Rams, Bears, Jets, and Browns have all gone this route to some extent.

To understand whether Spielman's approach is still a sound one, I decided to update a prior analysis I did on GM drafting performance. The analysis looks at player production (judged by Approximate Value) relative to the production that would be expected based on the player's experience and draft position. The results are then weighted so that accumulated production from players taken in older drafts doesn't outweigh more recent production. You can find more details on how this is calculated in the previous post.



The analysis considers players from the 2014-2017 drafts. The last four drafts are used because the players are still on rookie contracts, and are therefore likely to be underpriced relative to their production. After players are signed to second contracts, they are typically no longer significantly underpriced. The classic team-building philosophy is to acquire several quality starters on cheap rookie contracts while supplementing with a few expensive free agents at positions of need. Does this approach still work in the modern NFL?

Team Weighted Value vs Draft Capital Team Weighted Value vs Draft Capital Team Weighted Value vs Draft Capital Chiefs 205% Packers 154% Colts 116% Saints 194% Giants 146% Dolphins 116% Cowboys 185% Panthers 142% Cardinals 113% Vikings 178% Bears 137% Chargers 103% Jaguars 172% Raiders 136% Broncos 100% Falcons 167% Redskins 135% Jets 97% Lions 163% Buccaneers 131% Eagles 93% Patriots 163% Titans 120% 49ers 92% Steelers 159% Texans 120% Bengals 83% Rams 154% Seahawks 117% Ravens 82% Bills 117% Browns 78%

The chart above shows team drafting efficiency throughout the last four drafts. A few things stick out immediately. Of the top ten most efficient drafting teams, eight made the playoffs last year. The two that didn't, Detroit and Dallas, were close to making it in a very competitive NFC. On the opposite end, of the bottom ten teams, only one made the playoffs. That one team? The Super Bowl Champion Philadelphia Eagles. You will also notice that most team are getting more production relative to what Chase Stuart's draft value chart would expect. That's a question for a different day, but I'm guessing the new CBA makes rookie contracts even more valuable, causing more teams to play younger players than in the past.

It appears Spielman's philosophy of drafting well and supplementing through free agency is still a sound strategy that most good teams follow, but did the Eagles discover something the rest of the NFL has missed? I took a look at how each of the top four teams in 2017 were constructed to try and find out. The following chart shows the number of players that contributed marginal value to their team in 2017 (Approximate Values of 2+) organized by how the players were acquired. You can see a few commonalities among the top teams. The majority of contributing players were acquired through the draft, but all four teams had 10+ free agent contributors. The Vikings and Jaguars are built more with drafted players on rookie contracts, whereas the Patriots and Eagles have a significant number of drafted players on second or third contracts.

Vikings Players Patriots Players Draft: 2014-2017 9 Draft: 2014-2017 10 Draft: Prior to 2014 4 Draft: Prior to 2014 9 UDFA 1 UDFA 5 Free Agency 11 Free Agency 10 Trade 2 Trade 2 Jaguars Players Eagles Players Draft: 2014-2017 13 Draft: 2014-2017 8 Draft: Prior to 2014 1 Draft: Prior to 2014 7 UDFA 5 UDFA 2 Free Agency 10 Free Agency 12 Trade 0 Trade 3

What market inefficiency did the Eagles exploit to win the Super Bowl? They signed their own talented players at below-market deals. Five of their top ten players by Approximate Value were draftees on second contracts with contract values of below $10M per year. Jason Kelce, Fletcher Cox, Lane Johnson, and Brandon Graham could all be argued as top 2-3 players at their respective positions, and they are under contract for significantly under their true market value. The Eagles get a lot of publicity for the trades and free agent signings they've done recently, but the core of their team is still their drafted players.

The strategy for building a winner in the NFL hasn't changed as much as some claim. Finding undervalued assets is the key, and the most straightforward way to do so is by drafting well. But drafting well isn't the only way to succeed in the modern NFL. Signing your own free agents to below market deals, or finding other values via trades or free agency are also viable ways of building a winner. I hope Rick can continue his highly efficient drafting, supplemented with great free agent finds like Linval Joseph, Case Keenum, and Tom Johnson. If he does, the Vikings will continue to stay in great position to bring home their first Lombardi Trophy.