What happened to Marcus Peters?

Just a season ago, then-Kansas City Chiefs cornerback Marcus Peters was thriving. He graded as the 14th best corner in the regular season at 80.7 and stymied opposing quarterbacks who dared to throw at him — allowing a 66.0 passer rating (15th). He continued to rack up interceptions — it was his third straight year with five or more. But after being traded to the Los Angeles Rams this past offseason, Peters has struggled amid his team’s formidable defense (and offense). In the team’s first loss to the New Orleans Saints, Peters’ deficiencies were exacerbated.

Aside from the Rams’ game against the San Francisco 49ers, where he wasn’t targeted all game, Peters has allowed a passer rating of 100.0 or more in six of eight games when he’s the primary defender in coverage. He only had five such instances last year, and the situation appears even more concerning: He has already allowed six touchdowns, two more than he gave up in 2017, and has only one interception to show for it.

Peters was unable to control Saints wide receiver, Michael Thomas. After allowing six catches on eight targets to Thomas ranging anywhere from seven to 19 yards, Peters was beaten big when it mattered most late in the fourth quarter. Thomas simply ran past Peters in press coverage, and quarterback Drew Brees threw over Peters' head into Thomas’ waiting arms for a 72-yard score that was the final dagger to the previously undefeated Rams.

The Rams don’t have much to worry about at 8-1, but Peters’ uncharacteristic poor play could become a decisive factor come playoff time. He’s matched up against big-name receivers thus far: Thomas (90.7 grade), Davante Adams (82.5 grade) and Adam Thielen (90.8 grade). It’s a likely possibility that he’ll have to go another round against at least one of them when January rolls around. In the past two weeks, Peters has been targeted 20 times — tied for the most among cornerbacks in that span. Opposing quarterbacks have clearly taken notice his downfall.

That raises the obvious question: What changed for Marcus Peters? Or rather, what changed around Marcus Peters? For one, the big-play receivers he’s followed this year are seeing more targets (and more accurate targets) than the ones he stuck with a year ago. For example, in 2017, Antonio Brown was targeted just three times in Peters’ coverage for a measly two receptions for 14 yards. Brown finished with eight catches for 155 yards and a touchdown in that game, so clearly, Peters was at his best. DeVante Parker was targeted seven times against Peters in 2017, but only four were deemed catchable, and just two were caught.

This year, he’s seen nine targets (seven catchable) against Thomas, six (five catchable) against Adams and four (three catchable) against Thielen. In other words, NFC quarterbacks are testing Peters more than ever before with accurate throws, and he’s not coming away with interceptions, or success in general, at the rate he’s been used to.

In his rookie year, Peters was targeted a league-high 137 times (and he was the most targeted cornerback from 2015-2017). Peters had nine picks that year despite allowing eight touchdowns, compared to just one interception this season. Also, he only allowed opposing signal-callers to complete 50.4% of those throws in his coverage. This season, that number has ballooned to 72.3%. As for why the discrepancy between that year and this year exists is hard to say. But it appears that Peters’ move to the NFC may have something to do with it.

Through nine weeks, Peters has a 45.6 grade which ranks 106th of 111 cornerbacks, and his near-perfect passer rating allowed of 145.6 is 107th. He’s also already allowed more yards in coverage this year than in all of 2017. It’s been a staggering tumble from stardom for him — but it’s truly the best-case scenario as he attempts to make the climb back to glory. His team is considered a title contender and his offense and defensive line are playing lights out. Now, it’s a matter of whether Peters can get right in the next seven weeks before his team has to prove itself in a playoff run.