Not many teams can enter a game against the Green Bay Packers and truly, genuinely feel confident about their chances to win. That's especially true for a team like the San Diego Chargers, who ranked 18th entering Week 6 in our numberFire Live; no team had worse odds on kickoff Sunday afternoon. And really, the Chargers never had a chance to win the game even while it was being played -- they peaked at a 48.95 percent win expectancy in the third quarter and never went above 50 percent.

But Philip Rivers did his best to avoid letting the game feel out of hand at any point and helped San Diego come within three yards of a tie game at the end of regulation.

On the way to the eventual 27-20 loss, Rivers attempted 65 passes (tied for seventh most in NFL history for a single game) and completed 43 of them (tied for second in NFL history, two shy of Drew Bledsoe’s record of 45), which went for 503 passing yards (tied for 15th most in NFL history). Rivers did all that while not throwing an interception, just the fifth time a player has thrown for at least 500 yards without a pick, according to the Pro-Football-Reference Play Index. Ben Roethlisberger has done it twice.

It was a historic effort but one that will likely be forgotten sooner than it should because the result was a loss. While it’s still fresh and enough people will still care to remember, let’s take a look at how and why this performance happened.

Rolling on the Rivers

Rivers was easily the best quarterback of the week, by Sam Bradford, Cam Newton and Drew Brees.

When looking at some other numbers heading into the week, San Diego's eventual game script was pretty predictable. Through the first five weeks of the season, no quarterback had dropped back more than Rivers, who was tied with Blake Bortles for the league lead at 203. Only six quarterbacks in total had dropped back at least 200 times for the season, and none had more Pass Successes (111) or a higher Success Rate (54.7 percent) than Rivers -- Success Rate is the amount of plays that positively impact NEP. Eli Manning (52.2 percent) was the only other quarterback with 200 drop backs and a success rate over 50 percent.

San Diego can have Rivers drop back so many times because he’s able to, and he nearly has to in order for the offense to move the ball. The Chargers entered Week 6 as the ninth best passing team in the league by Adjusted NEP per play. The other part of the offense, the one responsible for gaining yards on the ground, entered the Packers game ranked 29th.

Among the top 10 passing offenses by Adjusted NEP per play, only three teams also have a running game that has produced negative value by the same metric, but none worse than San Diego’s.

Running Out of Run Support

That run game, as it’s been for most of the season, was a leading reason why the Chargers had to rely on the arm of Rivers so much. While the offense was gaining yards at will through the air, the running game could not get going. It was the opposite of what teams have been able to do this year against Green Bay, who came into the game ranked seventh against the pass and 31st against the run by Adjusted NEP per play.

Chargers running backs carried the ball a total of 21 times -- seven each for the three backs in rotation -- and gained 60 yards. Melvin Gordon led the way with 29 yards, followed by Branden Oliver with 23. The most disappointment came from Danny Woodhead who ran for eight yards with a long of four.

Woodhead’s worst runs -- in context, not yardage -- came late in the game on the final drive. Woodhead was involved in three of the final four offensive plays of the game for the Chargers, two of them running plays. On first-and-goal from the Green Bay 3-yard line, Woodhead gained a single yard and dropped San Diego’s win probability by 2.15 percent.

Two plays later on third down, Woodhead got another carry, losing another yard and 6.17 percent of win probability before a failed fourth down pass essentially ended the game. After Rivers drove the ball down the field -- not only on the final drive but for much of the game -- the Chargers kept two of their most meaningful plays on the ground, and like for much of the game, it did not work out.

The lack of run game in a such a passing performance isn’t exactly unique, though. Back in 2006, Ben Roethlisberger had a strikingly similar performance against the Packers in Week 15. In the game, Roethlisberger threw for 503 yards and no picks but needed a last-second, 19-yard touchdown pass to Mike Wallace to eclipse 500 passing yards and sneak out a 37-36 win with the extra point. Pittsburgh had 19 rushing attempts for 65 yards.

Considering the lack of run support, what Rivers and the rest of the offense was able to accomplish was very impressive.

Keenan Allen (14 receptions for 157 yards on 15 targets, our second-best wide receiver of the weekend by NEP), Antonio Gates and Malcom Floyd (95 receiving yards each) were all able to get themselves open against the Packers despite little threat of the run. Throughout the game, the Green Bay defense began selling out to stop Rivers, mixing up defensive looks from a four-man rush to zone blitzes to a three-man rush to a six-man blitz to throw the passing game off from play to play, but not much worked, and the Chargers kept to the air.

Statistically, the play wasn’t even the best of the year. Eli Manning and Josh McCown both had higher NEP in a single game last week alone, but it was another underrated performance by one of the most underrated quarterbacks in the league.

The Chargers didn’t win, but they never really had a chance.

Philip Rivers just made it feel that way.