The success of a team is almost always a function of player talent and performance (especially quarterback), injuries, turnover ratios, coaching and the like. In this article, I will explore whether there are also any “hidden” advantages resulting from the way a team builds its roster.

Teams included in the analysis for this article were the final four 2013 playoff teams (Seahawks, Broncos, 49ers, Patriots) and the two teams (Texans and Redskins) with the worst 2013 records. Various metrics related to a team’s roster were reviewed, and the full results are shown at the end of this article. Except where noted, all comparisons and percentages are based on 2013 scrimmage plays.

Metrics Used in the Analysis

Several metrics were analyzed used for the purpose of assessing whether there were quantifiable differences between playoff teams and losing teams. These metrics are described as follows:

· Continuity
-This metric is the percentage of scrimmage plays from holdovers (players who were on the team in 2012), drafted and undrafted rookies and veteran free agents.
-This measures the turnover in personnel from 2012 to 2013 and the source of roster additions.

· Experience
-This metric is the percentage of scrimmage plays from players grouped by the year of entry into the league.
-This measures the level of a team’s experience.

· Pedigree
-This metric is the percentage of scrimmage plays from players grouped by the round in which they are drafted (undrafted free agents are also included).
-This measures a team’s reliance on, and accumulation of, high draft choices.

· Retention
-This metric is the percentage of scrimmage plays from players who are still playing for the team that originally drafted them.
-This measures a combination of the team’s experience and the ability to retain players after their initial contract expires.

· In-Season Stability
-This group of metrics is less about building a roster than it is about the demands that injuries place on a roster.
-Four individual metrics are used in this area, with the singular purpose of measuring the stability of the starting lineup in the 2013 season.
   -The first metric reports the number of players who started 15 games or more
   -The second metric reports the number of players who participated in at least 500 scrimmage plays
   -The third metric reports the number of players who participated in at least 800 scrimmage plays
   -The final metric reports the total number of 2013 games started by players who started the first game of the 2013 season, split by offense and defense

Conclusions

Here are conclusions, and relevant background information, regarding the metrics used in the analysis:

· Continuity
-The Redskins had the highest percentage (90.6%) of scrimmage plays by holdovers with the Broncos being the lowest (77.2%)
-The Patriots have the highest percentage of scrimmage plays from rookies (13.9%) and the Broncos had the lowest (4.3%)
-The four playoff finalists all had a higher percentage of scrimmage plays from veteran free agent signings than the losing teams
-The implications of the above are that:
   -A moderate level of turnover is best, and probably a necessity due to free agency
   -Do not rely on rookies
   -The signing of veteran free agents to fill holes is essential
· Experience
-The Seahawks had only 9% of its scrimmage plays from players who entered the league in 2006 or earlier, one-half the next closest team (the Broncos)
-65% of the Seahawk’s scrimmage plays were from players who entered the league in 2010 or later, with the next highest being the Texans (58.4%)
-The 49ers and Redskins were the most experienced teams with each having about 40% of their scrimmage players from players entering the league in 2010 or later
-Other than the Seahawks’ youth, there was no other noteworthy differences between winners and losers
· Pedigree
-The 49ers had players with the highest pedigrees, with 42% of their scrimmage plays coming from first round players followed by the Texans with 30%
   -67% of 49ers scrimmage plays were from players taken in first three rounds
-The Seahawks had the lowest percentage of scrimmage plays by first round players at just over 15%, but had the highest percentage among both second round and third round players
-The most significant difference between the playoff teams and the losing teams is that the playoff teams all had a higher percentage of undrafted free agents on their roster, with the Patriots highest at 31% and Texans lowest at 6.5%
   -Is this because the winning teams (1) do a better job of scouting and signing undrafted free agents, (2) give them more an opportunity to play or (3) are just plain luckier?
· Retention
-The Texans had the highest retention rate with 66%, followed by the Seahawks at 60%
-The Redskins had the lowest retention rate at 43%
-The retention rate is affected by both the quantity and quality of a team’s draft selections
-There was nothing here to suggest that this is a significant success factor
· In-Season Stability
-The 49ers probably had the greatest level of in-season stability with the highest number of players who started 15 or more games and highest number of starts by game one starters
-The Seahawks had only six players participate in 800 or more scrimmage plays, next lowest were Broncos and Texans, with 11 each
   -This could be due to substitution patterns (e.g., rotating front 3 or 4) as well injury
-Largely due to their injury situation, the Patriots had the lowest level of stability (only eight players starter 15 games or more), with the Seahawks not much ahead of them
-As shown by the Redskins, a high-level of stability is no guarantee of success
   -The key appears to be able to have sufficient depth to overcome those injuries that detract from stability
· Overall
-It does require any analysis to know that QB play is a key determinant of success, but this analysis was focused on more subtle advantages
-Probably the biggest difference between playoff teams and losing teams is the diversity of resources used to build their rosters
   -Playoff teams were more apt to fill holes with veteran free agents
   -Playoff teams were more likely to utilize undrafted free agents
   -This diversity enables playoff teams to overcome injury issues as both the Patriots and Seahawks had serious injury issues in 2013

(1) The difference for the Patriots between rookies and 2013 entrants was the signing of DL Chris Jones, who was not counted as a veteran free agent signing rather than a rookie since he played for another NFL team before coming to the Patriots.

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