​As the Giants get ready for a crucial four games that will probably seal their fate for the 2009 season -- the Falcons this Sunday in the Meadowlands, the Broncos at Denver, then the Cowboys and Eagles back in New Jersey -- they have two major puzzles to solve.

Everyone knows about the defense: Big Blue's D has allowed a whopping 123 points in the last four games, all losses -- 52 more than they allowed in the first five games, all victories. What hasn't been as obvious is that the offense, or more specifically Eli Manning, has fallen off just as sharply. The highest paid quarterback in the NFL was on fire in the first five games, averaging over 240 yards per game; in the last four, it's been 214.5 yds/game. But that doesn't tell the whole story.

In games one through five, Manning completed 64.4 percent of his passes for a spectacular 8.98 yds/throw -- far and away the best YPP average of his career -- with 10 touchdowns against just two interceptions.

In the last four games, against New Orleans, Arizona, Philadelphia and San Diego, Eli's gone south faster than a Canadian goose -- just 81 of 123 completed for a 55.7 percent completion and a dismal 6.13 yards/throw. He's thrown just five TD passes against six interceptions.

We don't know which is the bigger problem, the defense or Eli, but the Giants aren't going to win anything without a fast turnaround from both. They should beat the Falcons -- they're six-point favorites and playing them at home -- but the Denver game will be treacherous as the Giants face a team that's performed better this year and has the biggest home field advantage of any in the NFL. That means the Giants may have to beat both the Cowboys and Eagles just to stay in playoff contention. (The last game of the year is against the Vikings in Minnesota.) And if they lose to Atlanta, fans can officially begin to despair.