Beyond strictly looking at wins and losses, DVOA by Football Outsiders gives a clear picture of team performance.
The following Infographic shows the past 10 years of DVOA rankings (2008-2017) for the Los Angeles Chargers.
The Chargers have held on during the second half of Philip Rivers' career with a few dips and surges, but they have only reached the playoffs once since 2009.
Ten-Year DVOA Rankings: Arizona Cardinals, Atlanta Falcons, Baltimore Ravens, Buffalo Bills, Carolina Panthers, Chicago Bears, Cincinnati Bengals, Cleveland Browns, Dallas Cowboys, Denver Broncos, Detroit Lions, Green Bay Packers, Houston Texans, Indianapolis Colts, Jacksonville Jaguars, Kansas City Chiefs, Los Angeles Rams, Miami Dolphins, Minnesota Vikings, New England Patriots, New Orleans Saints, New York Giants, New York Jets, Oakland Raiders, Philadelphia Eagles, Pittsburgh Steelers, San Francisco 49ers, Seattle Seahawks, Tampa Bay Buccaneers, Tennessee Titans, Washington Redskins