Best and worst QBs of Week 4: Trubisky jumps from worst to first

Riddick sounds off on Goff's early detractors (1:52)

Louis Riddick says people were quick to judge Jared Goff after his rookie season and credits the partnership of Goff and Sean McVay. (1:52)

Any given Sunday ... every quarterback has a shot to sit atop the Total QBR leaderboard. While QBs are most often judged by wins and losses or touchdowns and interceptions, we like to rank them every week by the stat that measures their per-play contribution to their team's cause.

An explainer of QBR can be found here, but the main idea is to capture more elements of a quarterback's play than traditional methods consider. QBR includes the value (or lack thereof) of quarterback rushing, sacks, fumbles, relevant penalties and -- crucially -- the down and distance of every play. QBR works on a 0-to-100 scale, with 50 roughly average and 75 about Pro Bowl-caliber play.

Each Tuesday in this space, we'll highlight the best and worst QBR performances from the NFL weekend and break down what made each quarterback perform at either extreme.

Which quarterbacks were the best and worst of Week 4?

Top 3

1. Mitchell Trubisky, Chicago Bears

Total QBR: 98.2

Note to NFL defensive coordinators: Pressure Trubisky.

Although the former Tar Heel might not scare defenses yet, he and coach Matt Nagy made the Bucs pay when the young QB wasn't under duress on Sunday. It's easy to figure that all quarterbacks are better with a clean pocket, but Trubisky was particularly effective in that situation. He threw only four passes while under duress in the Bears' blowout win.

At 24 years, 41 days, Trubisky became the second-youngest quarterback to throw six touchdown passes in a game, behind only Patrick Mahomes (22 years, 364 days), who did so in Week 2. Trubisky finished last season 29th overall in Total QBR (32.4). -- Walder

2. Jared Goff, Los Angeles Rams

Total QBR: 95.0

Before the season, some thought Goff was an average quarterback with an outstanding supporting cast. Maybe it's time to start thinking that the Rams are so great because of Goff.

He tore up a Vikings defense that FPI still really likes. Like Trubisky, he has the benefit of an innovative coach and offense. The former Cal product was outstanding on play-action in the shootout Thursday night, and that actually has been the case all season, as Goff ranks second in QBR on such passes. -- Walder

3. Jameis Winston, Tampa Bay Buccaneers

Total QBR: 90.8

At first glance, Winston's stat line does not seem overly impressive: 16-of-20 passing for 145 yards with one touchdown and a pair interceptions -- all in garbage time after the Bears battered Ryan Fitzpatrick.

One of the unintended consequences of attempting to suppress padding stats in garbage time is that if the quarterback plays only in garbage time, nothing ends up with a lesser impact on his overall efficiency. The idea of down-weighting garbage time works when the quarterback has played when the game was competitive, thus giving more weight to plays that happened when the game was in question.

Winston's entire day came not only in garbage time but also at the extreme end of garbage time, with him not running a single offensive play on which the Buccaneers' win probability was above 1 percent. He also played the Bears, who had allowed opposing quarterbacks a 35.9 Total QBR, fourth-lowest in the league, through the first three games of the season.

The combination of playing efficiently against a defense that had not allowed an unadjusted QBR above 50 and effectively not having any of the plays down-weighted pushed Winston into the top three for the week.

Moreover, it's not as if Winston was terrible. He completed 80 percent of his attempts and averaged 7.3 yards per attempt, and he converted a pair of fourth downs via passes. -- Gargiulo

Just missed: Kirk Cousins, Minnesota Vikings (86.4); Deshaun Watson, Houston Texans (86.0)

Bottom 3

1. Ryan Tannehill, Miami Dolphins

Total QBR: 4.5

Things started well for Tannehill and the Dolphins on Sunday against the Patriots. He connected on his first attempt of the game, a 22-yard gain to Kenny Stills (18 air yards). Then the rest of the game happened.

Tannehill didn't complete another pass of at least 15 yards downfield for the duration and had only three more passing first downs en route to his worst Total QBR since his first career start (a 4.1 at Houston in Week 1 of 2012). He also couldn't cleanly handle a snap midway through the second quarter, which the Patriots jumped on for his most damaging play of the game in terms of expected points added. That dropped him from a raw QBR around 16 to below 4, where he hovered for the rest of the game. -- Gargiulo

2. Josh Allen, Buffalo Bills

Total QBR: 5.1

Allen wowed NFL scouts with his throwing strength during the pre-draft process.

The problem? A cannon for an arm matters only if the ball goes to the right team. When Allen chucked it deep -- 15-plus yards downfield -- against the Packers on Sunday, he ended up completing more passes to defenders than he did to his own teammates. Those interceptions were two of Allen's three most costly plays of the day, with a fumble on a short run sandwiched between.

Allen now has the lowest Total QBR (23.7) among all qualified starters this season. -- Walder

3. C.J. Beathard, San Francisco 49ers

Total QBR: 23.4

Making his first start of the season for the injured Jimmy Garoppolo, Beathard picked up right where Garoppolo left off. Unfortunately for the 49ers, that means an inefficient performance and a close loss. Only the Bills have a lower team Total QBR through four weeks than San Francisco.

Beathard also was the recipient of some unfortunate luck. To start the second quarter, he seemingly was tripped by one of his own offensive lineman and couldn't make a clean handoff to Matt Breida. Beathard was charged with the fumble.

Beathard's first interception also wasn't completely on him (QBR takes that into account but doesn't completely absolve him), as Garrett Celek had a pass hit him in the hands before it popped up into the air for Los Angeles to intercept. Late in the fourth quarter and trailing by two points, Beathard was hit while throwing, and the ball found its way into a defensive lineman's hands for a second interception at a crucial juncture -- again not all on him but not something QBR will completely ignore. -- Gargiulo

Just missed: Sam Darnold, New York Jets (24.1); Ryan Fitzpatrick, Tampa Bay Buccaneers (27.9)