Quick Reads: Context is everything

Michael Vick had a great day against Jacksonville. But should it have been even better? Doug Benc/Getty Images

Every facet of life seems to have its own "[insert phrase] is everything." For real estate, location is everything; in poker, it's position; in investing, it's timing. Ask the coach of an NFL team and he'll tell you winning is everything.

Ask us at Football Outsiders, though, and we'll give you a different answer: Context is everything. In a league in which more information and coverage is available on a daily basis than ever before, it's easy to come up with numbers to support most any opinion. Without the context of where those numbers take place and what predictive value they have going forward, though, statistics are toys of manipulation as opposed to illumination.

The most difficult piece of context to account for while watching games is the quality of the opposition. Although it's easy to tell how difficult it is to complete a pass against Darrelle Revis as opposed to, say, Sabby Piscitelli, it's extremely difficult to notice the small differences on a play-by-play basis from one defense to another, especially if you've seen only a small portion of the league's defenses play.

Those differences can end up having a dramatic impact on performance, though. The table below lists the statistics recorded by quarterbacks in 2009 against eight of the league's pass defenses. It starts with the team with the best pass defense DVOA, the New York Jets, and ends with the Detroit Lions' league-worst pass defense.

Context lowers the bar for ability, but it raises the bar for expectations. Last season, the average quarterback playing against the Jets threw for 168 yards on 31 attempts while completing just 51.8 percent of his passes. Against the Lions, he threw for an average of more than 272 yards on 34 attempts, and he completed 68 percent of his passes. The Jets gave up half a passing touchdown per game, and the Lions allowed an average of 2.1. A 200-yard game against the Jets would be above-average; against the Lions, it would be cause for disappointment.

The defense-adjusted yards over replacement (DYAR) begins to adjust for opponent strength after Week 4, so you'll begin to see opposition weighted at 40 percent of its eventual strength after next week. (It gets to 100 percent after Week 10.) There is one player, though, whose supposed "breakout" performances have not been seen very kindly by DYAR and who will only see his figures decline further once opponent adjustments come into play.

Three good performances

1. Michael Vick, QB, Philadelphia Eagles
It might be more instructive to say "Good, but not as good as you think, and probably a lot worse than it looks by Week 10." After two quarters of effective mop-up duty against a Green Bay Packers team with a very good pass defense, Vick has started games against the teams with the two worst pass defense DVOAs in the league last season: Detroit and Jacksonville. And neither has shown much to suggest improvement this season. For these sorts of teams, 270 yards and two touchdowns is an average performance, not a good one. And Vick has averaged 285 yards and 2.5 TDs per game -- slightly above average. But he also has had the league's 12th-best passing offense from a year ago to work with.

So a performance that ranked 10th in DYAR among starting quarterbacks this week (including rushing DYAR) is likely to drop even further once the woeful Jacksonville pass defense gets factored in. Although highlight shows featured what Vick did on his three completions of 42 or more yards, he was wildly ineffective at times.

On Philly's first four drives, Vick tossed a 61-yard touchdown pass to DeSean Jackson but otherwise went 2-of-8 for 6 yards with a sack. After an effective two-minute drill to get an 11-point lead, Vick led two possessions that combined for seven plays by going 2-of-4 for 22 yards and a sack, with both completions coming on third-and-long and ending up short of the sticks, leading to punts. He was only particularly effective once he got the ball back again, with 5:30 left in the third quarter.

That the Jaguars had scored only three points had nothing to do with Vick; that the Eagles had mustered only 14 was mostly on him. The great arm and athleticism are still there, and Vick has certainly improved his patience in the pocket. But it's easy to do that against a dreadful pass defense. We won't know much more about the player Vick actually is until we see him against better pass defenses, starting with the Washington Redskins this week.