NFL Week 6's worst QB performances: Dak Prescott disaster-class sinks Cowboys against Lions

The majority of Nix's production came after the game had been decided. The Chargers (3-2) led 20-0 at the half, when Nix was 3-of-10 for 22 yards and an interception.

He led two meaningless fourth-quarter touchdown drives to improve his final stats (19-of-33, 216 yards, two touchdowns and an interception), but Nix's horrendous start is what stood out.

Dallas Cowboys QB Dak Prescott

Prescott's day turned on an ugly first-quarter red-zone interception.

He began his team's 47-9 blowout loss to the Lions 8-of-10 for 98 yards, leading Dallas deep into Lions territory at their seven-yard line on the Cowboys' second possession.

But on a 3rd-and-5, Prescott badly missed wide receiver CeeDee Lamb, lofting a pass easily intercepted by Lions safety Brian Branch. Had Prescott thrown toward the back-left pylon, Lamb would have scored a touchdown to give Dallas the lead.

After that play, Prescott went 9-of-22 for 80 yards and another interception before being pulled for backup Cooper Rush.

Cleveland Browns QB Deshaun Watson

We have to give Browns head coach Kevin Stefanski credit. While he should bench Watson, his inaction makes our job easier. As long as Watson is Cleveland's starter, we have one less spot to worry about on our weekly list. 

Against the Philadelphia Eagles on Sunday, Watson avoided turnovers but showed poor awareness while taking five sacks, increasing his total to 31 this season (the most in the league).

Late in the second quarter of the 20-16 loss, Watson ran straight into a rushing defensive lineman to his right instead of moving to his left, where he would have had space to operate.

During the FOX broadcast, the network shared that the Browns had a stretch of 26 consecutive failed third-down conversion attempts with Watson at quarterback this season before finally notching a successful attempt on a 3rd-and-10 with 1:04 remaining in the third quarter.

Per former Pro Football Focus analyst Austin Gayle, Watson has this season produced the fewest expected points added on dropbacks (-66.2) since 2000, eclipsing former No. 1 overall pick JaMarcus Russell in 2009.

Watson averaged five yards per dropback against Philadelphia, going 16-of-23 for 168 yards and gaining 17 yards on four carries while losing 24 yards on his five sacks.

Without running back Nick Chubb — and due to Watson's exorbitant price tag — the Browns (1-5) have relied on the inefficient quarterback to be their primary source of offense this season. The results have been as poor as anyone could predict, with Cleveland averaging 15.8 points per game.

Tennessee Titans QB Will Levis

Every time Levis plays, he shows why his mayonnaise obsession might be the most normal thing about him.

Little that he does on the football field makes sense. In a 20-17 loss to the Colts (3-3), Levis was 16-of-27 for 95 yards, one touchdown, one interception and the season's most awkward celebration when he pretended to be Spider-Man, shooting invisible spiderwebs from his wrists.

He also crushed a sideline worker's leg on a wild flip out of bounds, resulting in a stoppage of play and the staff member being carted off the field.

Levis is as much a danger to people off the field of play as he is to the Titans on it. His latest chaotic performance did little to suggest Tennessee wouldn't be better off finding his replacement during the offseason.

Tampa Bay Buccaneers QB Baker Mayfield's second quarter

Tampa Bay had a franchise-record 594 yards in a fully inebriated 51-27 win in New Orleans against the Saints. 

The Bucs scored the game's first 17 points and its final 27, but Mayfield's disastrous second quarter gave the Saints (2-4) life.

Mayfield was 10-of-19 for 133 yards, one touchdown and three interceptions in the quarter, making several poor decisions that New Orleans' opportunistic defense took advantage of.

Mayfield was nearly flawless during the other three quarters, though, when the Bucs outscored the Saints 44-0.

In the first, third and fourth quarters, Mayfield was 14-of-17 for 192 yards and three touchdowns. But during the second, Mayfield was possessed by some sinister force — or Jameis Winston's ghost. 

It wasn't enough to sink the Bucs against the fading Saints, but better teams might not be as forgiving.