Here's our weekly deep dive into NFL quarterback play. Many thanks to our friends at ESPN Stats & Information for supplying analysis and data to drive this post. Remember that Total QBR runs on a scale of 0-100. The scale for traditional passer rating is 0-158.3.
Passer rating: 146.0
Analysis: In three quarters against the Philadelphia Eagles, Manning threw 34 passes. He completed 27. Two were judged to be off target: either underthrown or overthrown. On the season, Manning has completed 117 of 156 passes (75 percent) with just 14 off-target throws. That's one more way of demonstrating Manning's lethal opening to this season. His 16 touchdown passes are the most in NFL history through four games, and he has tied the league record for the most touchdown passes without an interception to start a season. Sunday was Manning's 24th career game with four or more touchdown passes, one more than the next-highest qualifier (Brett Favre). On Sunday, it helped that his offensive line kept him away from duress on all but two of his drop-backs.
Passer rating: 130.0
Analysis: Locker was having one of the best games of his career before a hip injury forced him out with 11 minutes, 14 seconds remaining in the third quarter. To that point, Locker had already thrown three touchdown passes and completed 18 of 24 passes. He converted 7 of 9 third-down throws, including two for touchdowns, and connected on 5 of 6 attempts against the New York Jets' blitz. Still, the injury could have significant repercussions for his future. Injuries limited him to 11 games in what was supposed to be his first full season as a starter in 2012 and, all told, he has played in only 20 of 38 possible games since being drafted in 2011. If the hip is a long-term injury, should the Tennessee Titans count on him to stay healthy in 2014?
Passer rating: 120.3
Analysis: Rivers rebounded and finished strong after the Dallas Cowboys returned an interception for a touchdown in the second quarter, completing 20 of 24 passes for 249 yards and two touchdowns after that point. His deep touchdowns to running back Danny Woodhead (26 yards) and tight end Antonio Gates (56) were perfectly placed. Overall, Rivers completed 35 of 42 passes for 401 yards. His completion percentage of 83.6 was the highest in NFL history for a 400-yard passer. Perhaps most importantly, the interception was his only turnover. After committing 47 turnovers the past two seasons, Rivers has only two in 2013.
Passer rating: 123.4
Analysis: Cassel completed all 10 of his second-half passes as the Minnesota Vikings held off the Pittsburgh Steelers. He also capitalized when the Steelers put eight men in the box to defend tailback Adrian Peterson, which they did on a season-high 57 percent of the snaps -- more than Peterson has faced in any game over the past two seasons. On those plays, Cassel completed 7 of 10 passes for 77 yards and a touchdown. Really, that's all the Vikings ask of their quarterback: to take advantage of favorable situations. Cassel did that, and it could mean a more permanent change in the Vikings' starting lineup.
Passer rating: 65.6
Analysis: "Bad Jay" reappeared after three weeks of good behavior (i.e., sound play) under new coach Marc Trestman. Flustered by the Detroit Lions' heavy pressure, Cutler forced the ball downfield too often. Almost half (45 percent) of his passes traveled more than 10 yards downfield, up from 29 percent over the first three games, and his average pass traveled 12.3 yards downfield -- up from 7.0 yards in Weeks 1-3. Cutler accounted for four turnovers and converted only one third down via passing. The Lions surely played a role in that performance, but Cutler seemed to forget the safety nets built into this offense.
Passer rating: 46.4
Analysis: Flacco threw a career-high five interceptions in a loss to the Buffalo Bills, and it wasn't as if he was forcing the ball downfield. Four of them came on passes shorter than 15 yards past the line of scrimmage. (He also continued to struggle on downfield passes, completing just 4-of-15 that traveled 15 or more yards downfield.) The Ravens abandoned the run game, throwing on 85.8 percent of their plays, allowing the Bills' defense to settle in the intermediate route area. Two of Flacco's four sacks were especially significant, coming on first down in the fourth quarter of a one-score game.
ROUNDING OUT THE WEEK:
Passer rating: 119.8
Briefly: Brady discovered the deep ball against the Atlanta Falcons, completing seven passes that traveled at least 15 yards downfield -- including four to Kenbrell Thompkins and one for a touchdown. He had connected on six such throws over the first three games.
Passer rating: 115.7
Briefly: The San Francisco 49ers got back to using Kaepernick as part of their offense, rather than their centerpiece, Thursday at the St. Louis Rams. He attempted just 23 passes, tied for his second lowest in an NFL start, but threw for two touchdowns and accounted for just one turnover.
Passer rating: 108.4
Briefly: Romo connected on a 34-yard touchdown pass to receiver Dez Bryant, but it was his only completion of the day on passes that traveled more than 14 yards downfield. He also managed just two completions on seven third-down passes.
Passer rating: 90.0
Briefly: Luck helped ensure that a 20-3 halftime lead stood by completing all eight of his third-quarter passes against the Jacksonville Jaguars.
Passer rating: 90.6
Briefly: A total of 383 yards wasn't enough against the Vikings, in part because he fumbled at the 11-yard line with 6 seconds left and a chance to tie the game. He threw eight screen passes, completing all eight, and connected on all 12 passes to receiver Antonio Brown, but the Steelers are still 0-4.
Passer rating: 103.9
Briefly: Hoyer had a strong game against the Cincinnati Bengals' stingy defense, taking three sacks but committing no turnovers. He completed 9 of 13 passes on third down, converting seven for first downs, and connected on all five passes in the fourth quarter to hold off the Bengals.
Passer rating: 84.2
Briefly: Smith and the Kansas City Chiefs had strong success in play-action, connecting on 6 of 10 such attempts for 92 yards and two touchdowns. This was the case even though the Chiefs had only 19 rushing attempts by their running backs. He also threw all three of his touchdown passes on third down.
Passer rating: 91.7
Briefly: Ryan had good luck targeting tight end Tony Gonzalez, connecting on 12 of 13 passes to the TE. Ryan missed on 16 of 38 passes to all other receivers. He did throw for 200 yards during a fourth-quarter comeback that fell just short.
Passer rating: 83.6
Briefly: Short passes, followed by yards gained after the catch, are supposed to be the hallmark of coach Chip Kelly's offense. On Sunday, Vick missed on 6 of his 11 attempts that traveled 5 or fewer yards downfield. He also didn't complete a third-quarter pass as the Eagles fell behind by 29 points.
Passer rating: 81.6
Briefly: Schaub played a big role in staking the Houston Texans to a big lead over the Seattle Seahawks, tossing two second-quarter touchdowns. But he also threw two interceptions on third down, including a weak pass to the flat that Seahawks cornerback Richard Sherman returned for a game-tying touchdown with two minutes, 40 seconds left. It dropped the Texans' win probability from 95.1 to 56.7 and was one of the worst and costliest throws of the NFL season.
Passer rating: 83.3
Briefly: Stafford was simply off target on a number of throws that could have gone for long gainers against the Bears, and most of his completions (19-of-23) came on passes that traveled 10 or fewer yards downfield. He completed only 2-of-7 on third down.
Robert Griffin III
Passer rating: 91.7
Briefly: The Washington Redskins' extra commitment to the running game paid off for Griffin. They ran on 48 percent of their plays, and 40 percent of the time when trailing Sunday, as compared to 26 percent and 21 percent, respectively, over the first three weeks. As a result, Griffin completed 10 of 13 play-action passes for 113 yards.
Passer rating: 62.2
Briefly: Hooray for remembering that Larry Fitzgerald is on the roster! Palmer didn't target Fitzgerald in the first half but then looked for him nine times in the second, connecting on six receptions for 68 yards and the game-tying score. As a result, Palmer threw for 180 of his 248 yards after halftime.
Passer rating: 58.2
Briefly: The Bengals tried to push the deep ball with receiver A.J. Green, but Dalton completed only 1 of 7 passes to him that traveled more than 10 yards in the air. Dalton averaged 4.9 yards per attempt, the third-fewest in a game for his career.
Passer rating: 59.2
Briefly: The Rams' downfield passing attack continues to be anemic, and Bradford managed just two completions on passes that traveled at least 15 yards past the line of scrimmage. But on Thursday night, he got no help from a running game that managed just 18 yards -- the lowest by an NFL team in a game this season prior to Sunday.
Passer rating: 64.8
Briefly: The good news is that Manning connected 10 times (on 16 targets) to receiver Victor Cruz. The bad news? Just about everything else. The Chiefs put him under duress on 12 of his 41 drop-backs, and he completed only two of those passes. In the crucial third quarter -- much of which was played with a three-point Giants deficit -- he missed on 11 of 13 passes and threw an interception.
Passer rating: 49.7
Briefly: The Texans really got after Wilson, sending at least five pass-rushers 52 percent of the time and putting him under duress on nearly half of his 34 drop-backs. He scrambled for 77 yards, the second-highest total of his career, but also took five sacks and managed 5.3 yards per attempt -- tied for the second-lowest mark of his career.
Passer rating: 55.7
Briefly: The Tampa Bay Buccaneers pulled way back on their downfield passing ambitions in Glennon's first start. His 43 attempts averaged 6.6 yards past the line of scrimmage, down from 10.9 yards with Josh Freeman. All told, 72 percent of Glennon's passes traveled fewer than 10 yards downfield, and he did not complete a pass that traveled more than 14 yards past the line of scrimmage.
Passer rating: 48.9
Briefly: Manuel committed three turnovers, but fortunately for the Bills, that total was lower than Flacco's. Manuel completed only 4 of 13 passes that traveled more than 5 yards downfield.
Passer rating: 79.2
Briefly: Four turnovers and four sacks among 40 drop-backs, including a ridiculous attempt to switch the ball to his left hand behind his back, did in the Jets against the Bills. Smith has 11 turnovers in four games this season, at least as many as every NFL team except the New York Giants.
Passer rating: 83.7
Briefly: After all the free-agent money Flynn has made, would you believe that Sunday was his second NFL start? Flynn had little chance to operate, taking seven sacks on 40 drop-backs, including six against the Redskins' standard four-man rush. Terrelle Pryor's mobility never looked better.
Passer rating: 30.6
Briefly: Gabbert's return to the lineup yielded no new observations about his capacity. He did not complete a pass in six attempts against the Indianapolis Colts' blitz.