Philip Rivers is one of the best quarterbacks in the NFL. No surprise there. But it always feels like he doesn't get the credit he deserves.

Maybe it's because he plays on the West Coast. Maybe it's because Rivers has played in only two playoff games since the start of the 2010 season. Whatever the reason, Rivers, despite putting up solid season after solid season, is usually left out of the conversation when discussing the game's elite passers.

Maybe that will change after this year.

At least it should -- because Rivers is having a heck of a year, one of the best of his career. And his play is a big reason why our metrics view an undermanned San Diego Chargers team -- particularly on offense -- as one of the league's better squads.

By the Numbers

Among passers with at least 100 drop backs this year, Rivers ranks sixth in Passing Net Expected Points per drop back. Net Expected Points, or NEP, is our in-house metric that shows the points a player adds to or subtracts from a team's expected total on every play on which they're involved.

This season, Rivers has increased San Diego's expected scoring by 0.23 points each time he drops back. The league average is roughly 0.13.

Again, among passers with at least 100 drop backs, Rivers is 5th in total Passing NEP and 11th in Passing Success Rate, which is the percentage of drop backs that result in positive NEP.

By our metrics -- any of them -- he's been one of the best in the game.

He also rates very well in more traditional stats. Rivers checks in fourth in Adjusted Net Yards Per Attempt (7.66), third in yards per completion (12.5), and fourth in ESPN's QBR (74.4).

This has been one of the best seasons of Rivers' illustrious career. He's posting a career-best interception rate (1.6%) while his Adjusted Yards Per Attempt (fourth), QBR (third) and 66.1% completion percentage (third) all rank among the best single-season clips of his 171-game career.

Depleted Weapons

Rivers is doing this despite losing a lot of his key weapons. Pass-game guru Danny Woodhead tore an ACL and stud wideout Keenan Allen did the same, Steve Johnson tore his meniscus, and Antonio Gates is a battered 1990 pickup truck -- he's still getting around, but it doesn't look good.

Rivers has lost his top pass-game option at running back, receiver, and tight end, with Gates relegated to spot duty.

What that has done is thrust some new players into bigger roles, and those newcomers -- namely Tyrell Williams and Hunter Henry -- haven't served as patchwork players; they've been big-time producers.

Rookie tight ends normally don't do much, but Henry has been an exception. With Gates banged up, Henry has gotten extended run, and he is tops in Reception NEP per target among tight ends with at least 25 targets.

Williams -- an undrafted free agent in 2015 from Western Oregon who entered the year with 2 grabs for 90 yards -- has been a stud. Among wideouts with at least 45 targets, Williams ranks second in Reception NEP per target, adding 1.01 expected points each time the ball is thrown his way. He also ranks 5th in Target NEP, which includes expected points lost on incompletions and interceptions when the player is targeted, and 14th in catch rate.

While Henry and Williams are good and deserve major props for performing at such high levels after taking on bigger roles, Rivers should also get some of the credit. After all, he's the dude throwing them the ball, and neither player was expected to do too much this year.

One-Sided Attack

Melvin Gordon has been a fantasy football stud this year, but don't let that trick you into thinking the Chargers have a good rushing attack. Shoot, don't let that fool you into assuming that Gordon is a really good running back.

Gordon's fantasy stardom pretty much boils down to touchdowns and volume. He is tied for the league lead with eight scores, and without Woodhead siphoning pass-game work, Gordon has turned into an every-down player. Other than touchdowns, just about every other statistic tells us Gordon and the San Diego rushing attack isn't very good.

Among the 37 backs with at least 45 carries, Gordon ranks 29th in Rushing NEP per carry and 33rd in Rushing Success Rate. This has led to San Diego slotting in 29th in Adjusted Rushing NEP per play.

Advanced metrics not your thing? Well, Gordon's 3.3 yards per carry ranks 32nd among runners with at least 40 attempts.

It may not be all Gordon's fault as, just like last season, the Bolts have had injury issues on the offensive line with King Dunlap, Chris Hairston, and Joe Barksdale all missing either a full game or part of a game. The offensive line issues obviously impact Rivers, too, and his 6.5% sack rate is the 10th-highest clip among all signal callers.

The point of all this is to say San Diego isn't very good at running the ball and that their offensive line isn't very good. So Rivers is putting up big-time numbers behind a shaky offensive line, without the support of a quality running game and despite throwing to a lot of second-string options. He good.

In the interest of full disclosure, we need to mention the Chargers' sturdy defense. San Diego ranks eighth in Adjusted Defensive NEP per play, led by what our metrics have as the eighth-best pass defense. The secondary has been stout despite the loss of Jason Verrett, a 2015 Pro Bowl selection and their top corner. It's been a big improvement from last year, when the Bolts' defense ranked 29th, according to our metrics.

The Rest of the Way

Despite being 3-4 and sitting in last in the AFC West, our metrics like the Chargers a lot. San Diego is 11th in our team power rankings, which are based on our nERD metric. The Chargers' nERD of 2.94 shows that, based on their efficiency, they should beat an average team on a neutral field by 2.94 points. The Chargers also have the fourth-best point differential in the AFC, outscoring their opponents by 21 points.

San Diego is really unlucky to be 3-4, especially when juxtaposed to the AFC West-leading Oakland Raiders. Despite their 5-2 record, Oakland has outscored their opposition by a meager five points this season, winning a pair of one-point games, and they are 21st in our power rankings.

But the standings aren't sorted by metrics and point differential; they're sorted by wins and losses. If Rivers is going to throw his first postseason pass since 2013, he's going to need that bad luck to turn around. We give the Chargers a 29.6% chance of making the playoffs, and historically, teams that are 3-4 make the postseason just 17% of the time.

So, despite an some amazing work from Rivers -- as well as Henry, Williams, and an improved defense -- this season, it looks like the Chargers will once again be on the outside looking in at the postseason, and another solid season from Rivers will get swept under the rug.