The NFL Draft by Numbers: Building through the draft?

With the draft fast approaching, I have been hearing more and more people talking and writing about "building through the draft": how important it is, how it's the key to success in the NFL, how dynasties are built off it and so on. The proof that is often offered in support is that this or that top team in this or that year did an excellent job on draft day - and I am sympathetic to that view. After all, the Cowboys laid the foundation for their run of three Super Bowls in the nineties by drafting each one of the Triplets with their first pick in three successive drafts, from 1989 to 1991. Thinking about this made me feel all warm and tingly inside.

Then I thought about the Saints and and their recent Super Bowl win, and looked up their numbers. Imagine my shock at seeing that of the 28 Saints players listed as starters at Pro-football-reference.com, 13 (!) were not originally drafted by the Saints.

I then looked at the 2007 Super Bowl winning Giants team: 13 of 27 starters not originally drafted by the Giants!

Doing a quick search on Google with 'NFL building through the draft' resulted in the following: Of the first ten hits displayed, 8 were about specific NFL teams, which made me think that this may not be such a big secret after all. One team, the Jets, was even mentioned twice. The Jets? 13 (again!) of their 25 starters last year were not originally drafted by the Jets, and they just added at least four more (that I know of) in L.T., Antonio Cromartie, Nick Folk and Santonio Holmes.

So I asked myself the question, is 'building through the draft' still a relevant concept today, or is it more or less a relic from pre-free-agency days?

Hmm, I think I smell a ... stat!

To understand just how much drafted players (vs free agents for example) contribute to the overall team success, I needed to find the right metrics. I didn't want to use a simple quantitative stat like games played to determine the contribution of drafted players. Instead I decided to use a more qualitative stat that reflected the total value of a player to the team, irrespective of the position played or the number of games played. As in my previous post (Moving Up by Trading Down) I will use the " Approximate Value" (AV) metric developed by Doug Drinen at Pro-football-reference.com (PFR).

In my own words: Approximate Value is an attempt to assign a value to any player at any position for any given year, by weighting position specific metrics (i.e. yards or points scored/allowed) with an indicator for durability (total games played and seasons as their team's primary starter) and quality (Pro Bowl and All Pro nominations) and then normalizing all this at a team level. Read up on it at PFR if you need to know more.

As I started crunching the numbers, I stumbled over a nice article on the New York Times Fifth Down blog by Chase Stuart from PFR, titled "Which teams build wisely?"

In it he looks at which teams are built through the draft, and which are built otherwise. Using PFRs AV metric he looks at what percent of a team’s approximate value came from players drafted by said team. You'll see in the table below that I've tried to replicate his numbers, and by and large they match.

A first glance at Chase's table showed the Cowboys ranked just inside the top ten in 2009, which can be taken as an indicator that a lot of the Cowboys' big performers came via the draft - or that a lot of the players acquired via trade or free agency underperformed - take your pick.

What surprised me was that Chase had bunched in two of the Cowboys' biggest performers last season, Tony Romo and Miles Austin, with the other free agents under 'players acquired through other means'.

Surely the fact that the Cowboys picked up Romo and Austin as UDFA after the draft should be credited to the Cowboys' ability to 'build through the draft'? I strongly believe that both the drafted players and the UDFAs like Romo and Austin should be used when looking at a teams' ability to scout, recruit and develop its own talent.

So I set forth to look at how much of every teams' Approximate Value in 2009 came A) from players drafted by the team, B) from players signed as UDFAs and C) from players acquired via free agency, trades and other means. Here are the - somewhat surprising - results:

Approximate Value by source of player, 2009 (click column header to sort)

Team		Total Approx. Value	% drafted	% UDFA	% own Talent Total	% FAs and trades
	Cowboys	244	64%	14%	77%	23%
	Colts	238	70%	25%	95%	5%
	Vikings	259	52%	7%	59%	41%
	Cardinals	207	66%	5%	71%	29%
	Browns	162	41%	8%	49%	51%
	Packers	246	71%	14%	85%	15%
	Saints	246	50%	7%	57%	43%
	Jets	252	56%	10%	65%	35%
	Eagles	217	63%	12%	74%	26%
	Seahawks	167	54%	11%	65%	35%
	Falcons	208	58%	8%	65%	35%
	Ravens	238	71%	3%	74%	26%
	Bills	178	57%	10%	67%	33%
	Panthers	209	70%	7%	77%	23%
	Patriots	247	58%	12%	70%	30%
	Giants	190	58%	8%	66%	34%
	Steelers	252	56%	10%	65%	35%
	Chargers	238	54%	30%	84%	16%
	Rams	129	53%	5%	59%	41%
	Bengals	201	57%	11%	68%	32%
	Broncos	205	40%	2%	43%	57%
	Lions	136	50%	4%	54%	46%
	Texans	207	61%	2%	63%	37%
	Jaguars	180	82%	4%	86%	14%
	Chiefs	166	41%	12%	53%	47%
	Dolphins	187	50%	10%	60%	40%
	49ers	213	70%	0%	70%	30%
	Buccaneers	146	60%	5%	65%	35%
	Titans	188	62%	3%	64%	36%
	Redskins	187	50%	8%	58%	42%
	Bears	179	61%	5%	66%	34%
	Raiders	147	59%	10%	68%	32%
NFL Avg		201	59%	10%	69%	31%

A couple of notes on the data.

• % drafted: Players in this pool are only players drafted by a given team and still playing for that same team. Eli Manning for example is counted in the 'FAs and trades' column because he was drafted by San Diego but plays for the Giants.
• % UDFA: To qualify as an UDFA in this ranking, a player has to still be playing with the team for which he played his first NFL regular season snap, and this is not necessarily the same team that signed him to his first NFL contract. After all, what's the use if you can scout and recruit, but not retain talent? Former Cowboys like Danny Amendola and Matt Moore fall in this category - they initially signed with the Cowboys, but then moved on to other teams where they played their first regular season NFL snaps. In these cases, the Saints and the Panthers get the credit for these two players in the columns above.
• % FAs and trades: Basically all other players who were acquired by their teams through free agency or trades.
• Sample size: Only players with a minimum AV of 1 point were considered for this breakdown. That's still 1,487 players, or an average of 46 per team.
  

Key Observations

There is hardly any correlation between the make up of your player pool and winning in the NFL. Just out of curiosity, I ran a regression for all the columns against regular season wins in 2009. The results:

I don't want to scare anyone away with too much math, so here are the results in non-mathematical terms: There is a slight chance that you will win more games if you have more 'own talent' on your team. Similarly, if you have more free agents on board, there's a slight chance that you'll lose more games.

Arguably, this is a little bit of a chicken and egg problem. The reason many teams are forced into free agency in the first place is the lack of quality in their own talent pool. But take note, the Saints and Vikings had a significantly below average level of 'own talent' on their teams last year, and it didn't hurt them. Is it sustainable? Ask me again when Brett Favre makes up his mind about playing next season.

As you look at the teams with a high level of own talent last year, you'll see some of the usual suspects at the top. The Colts, Packers and Ravens are all teams that like to build from within. Other teams high on the list like the Jaguars and the Panthers may have chosen this course of action more out of financial than strategic reasons.

Also, keep in mind that this table is merely a snapshot of last year, and is not necessarily reflective of the general franchise philosophy. Had I done a similar chart for the Cowboys last year, with T.O., Zach Thomas, Pacman, Anthony Henry and all the other FAs who've since left, Dallas would have been at 28% 'outside talent' instead of the 23% this year.

Finally, as you look at the % UDFA column, two teams stand out: the Colts and the Chargers. Obviously, some of their big name UDFAs like Jeff Saturday, Antonio Gates and Kris Dielman contribute to the high scores, but the scores are also indicative of a very solid talent acquisition approach. The Cowboys, despite a perceived propensity for the big free agent splashes, have quietly been grooming their own non-draft talent. Perhaps next year will see the emergence of another undrafted player in Kevin Ogletree, Stephen Bowen or an as yet unsigned UDFA.

In today's NFL there are many ways to build your franchise. Shrewd use of your draft picks, particularly the mid-round picks, to trade for potential high value players is one way to do it (Jets). Recruiting and developing UDFAs as a potential source of talent, and not just camp bodies, is another (Colts). Solid and sustainable free agency acquisitions are yet another avenue that may be worth pursuing (Saints).

But by sheer force of numbers, the draft remains the main source of new player material. Get it right and you are golden. Get it wrong and you may struggle to compensate through other means.

In the next and final installment of this Approximate Value mini-series, we'll use AV to grade the drafts of the last couple of years. Perhaps that's where we'll see a stronger link to winning.