You can find out a lot about a football team by looking at its worst games. In the case of the New York Giants, you can find that their pass defense has produced some of the most embarrassing performances of any team this season. You can also find that the Giants played most of those games without a key defender, a pass-rusher who has since returned to the field with a vengeance.
At Football Outsiders, we analyze every play of every game of the NFL season with a statistic we call DVOA (defense-adjusted value over average -- more information can be found here). Viewed through DVOA, the Giants' worst four games really stand out on their schedule: the two losses to Washington, the 49-24 beatdown they suffered at the hands of the Saints and the Week 14 contest against Dallas.
Wait, what? Dallas in Week 14? The 37-34 win that ended the Giants' four-game losing streak and saved their season, the key divisional victory that kept New York's playoff dreams alive? That was one of the worst games New York played this year? Sounds crazy, but yes, that was a bad game in many ways: a three-point victory against a team that finished the year 8-8, with a potential game-tying field goal blocked in the last minute. That's a worse performance than most of the losses on New York's schedule, including close defeats to playoff teams like San Francisco and Green Bay.
But is there a common thread? Absolutely. The main lapse apparent through these four games: