Football Outsiders has put together some statistics recently that I wanted to talk about briefly. The article talks about the amount of wide receivers teams used in certain sets, and the effectiveness of each respective formation.
First off, formation efficiency with regard to the number of receivers: in the NFL, FO notes, "Just as it's generally true that passing is more efficient than running, it also seems to be generally true that using pass-oriented formations (i.e., three or more wide receivers) is more efficient than using run-oriented formations (i.e., two wide receivers or fewer). In 2010, offensive plays run out of three-receiver sets were the most successful (13.4% DVOA), followed by plays with four or more wide receivers (9.4%), two wide receivers (7.2%), and finally one or fewer wide receivers (-1.0%). Although the top two formations were flip-flopped, the general trend was the same in 2009."
DVOA, Defense-adjusted Value Over Average, as described by FO, "breaks down the entire season play-by-play, comparing success on each play to the league average based on a number of variables including down, distance, location on field, current score gap, quarter, and opponent quality." While this number is a bit confusing, or abstract in nature, in simple terms, in 2010, 3-WR sets are more efficient than every other formation, NFL wide. In 2009, 4-WR sets were most efficient.
Here's how Seattle did, DVOA wise, in their different formations:
As can be expected, the Seahawks' offense was pretty bad in almost all of its formations. In their 0-1 WR formations, they ranked 24th in the league per DVOA. In 2 WR formations, 28th in the league. 3 WR, 26th in the league, and 4-5 WR, 14th. None of these numbers really surprise me much, though it is interesting to note they did a pretty good job in their 'spread' formations with 4+ receivers with an efficiency 2.3% over the average for the NFL.
Another interesting thing FO notes is the frequency each set was run with. As you can see above, the Hawks ran 2-3 WR sets 87% of the time. It should be noted that when Seattle was running these sets they were, predictably, near league-worst in efficiency. I only say 'predictably' because it's no secret the Seahawks' offense was abysmal for most of the season. It seems that they had more effectiveness when running their 'outlier' sets: 4- and 5-WR formations that the defense wasn't as prepared for. Just off the top of my head, it seems to me some of these formations included a tight end or two motioning out and running routes on the wing or in the slot as well, - the Hawks taking advantage of their athletic and versatile corps there.
Come to your own conclusions of what these numbers tell you: for me, all I see is that the Hawks were terrible on a leaguewide-average scale in the vast majority of their formations. In other words, when they were running their basic offense, they stunk. Something that will need to change in 2011.