We're about a quarter of the way through the regular season. The Philadelphia Eagles (4-0) went through the week unscathed, the Houston Texans (0-3-1) are still the only team without a win and a new era started at quarterback in Pittsburgh.
But Week 4 was marred by Tua Tagovailoa's concussion days after a head injury and an active investigation by the NFL and NFLPA into his return following the first incident. Week 4 concluded with every team in the NFC West gridlocked at .500.
How much of an influence did coaches have on the outcomes in Week 4? USA TODAY Sports examined the performances of several team coaching staffs.
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Here are their grades for Week 4:
Dallas Cowboys coaching staff: A
Rush is 4-0 as a starter in his career (3-0 this season) and is the first quarterback in NFL history to win each of his first four career starts and have a passer rating of 90 or more in each game.
Rush passed for 223 yards and had a season-high two touchdowns in a 25-10 win over the Commanders on Sunday.
Rush knows the Cowboys' offense well and he's playing with a lot of confidence. This deep 45-yard pass to wide receiver Noah Brown is a good illustration of that.
Cowboys offensive coordinator Kellen Moore hasn't adjusted the playbook much because Rush has shown the ability to make all the necessary throws and he's not playing tentative. Prescott's career yards gained per pass attempt is 7.6. Rush is averaging 7.2 yards gained per pass attempt this season.
It helps that the line has held up, allowing two sacks total in the three games Rush has started.
Furthermore, Rush is capable of extending plays similar to Prescott.
Cincinnati Bengals coaching staff: B
Zac Taylor and the Bengals adjusted their play calls the past two games, and it's contributed to two consecutive wins. Instead of calling passing plays that take a while to develop, Taylor has dialed up quick passing plays and receivers are running simpler routes. It has also helped quarterback Joe Burrow avoid sacks; he has been sacked three times over the past two games (once Sunday) after 13 in the first two games.
On this go-route, Burrow stood in the shotgun and had a quick 3-yard drop back before throwing to Higgins, who beat Dolphins CB Xavien Howard in one-on-one coverage.
Atlanta Falcons coaching staff: C+
Marcus Mariota was largely ineffective on Sunday. The Falcons quarterback completed 7 of 19 passes versus Cleveland. When Mariota was intercepted in the third quarter, Arthur Smith and the Falcons coaching staff proceeded to call 14 straight runs. The 14 straight runs led to a touchdown drive and another drive that ended in a field goal.
Falcons RB Caleb Huntley had eight carries for 54 yards and a touchdown in the drive following Mariota's interception.
The decision to play smash-mouth football proved to be a winning strategy. Atlanta beat the Browns 23-20.
Baltimore Ravens coaching staff: D
On fourth-and-goal from the 2-yard line with a little over four minutes remaining in a 20-20 game, coach John Harbaugh and the Ravens elected to go for the touchdown instead of opting for a short Justin Tucker field goal.
The choice proved to be a disaster.
Lamar Jackson's pass intended for wide receiver Devin Duvernay was intercepted by Bills safety Jordan Poyer. Buffalo then proceeded to march down the field on a 12-play, 77-yard drive and converted a short game-winning 21-yard field goal as time expired.
Harbaugh should've kicked an easy field goal and given his defense an opportunity to close out the game. However, it's tough to completely admonish Harbaugh for his decision because the Ravens had the worst defense in the NFL entering Week 3.
Another concerning issue for the Ravens (2-2): both their losses have come when they've had second-half leads of at least 10 points.
Miami Dolphins coaching staff: F
The Dolphins failed Tagovailoa. No player should return to a football game after hitting his head and displaying clear signs of an injury. Then Thursday night's game featured a frightening scene as Tagovailoa was carted off after a sack that left him in the fencing position. For the second time in four days, Tagovailoa suffered a head injury.
Tagovailoa shouldn't have been allowed to come back to the Week 3 game against the Buffalo Bills when he was ruled questionable to return with a head injury after a hit. Following that game, coach Mike McDaniel said Tagovailoa had back and ankle injuries. The NFLPA then announced it would launch an investigation into the handling of the concussion evaluation. Tagovailoa entered Week 4 questionable with back and ankle injuries.
Thursday's alarming incident could've been avoided. Health and player safety are much more important than wins and losses. Tagovailoa won't play Sunday and McDaniel said he is improving.
This incident was the impetus for the NFL and NFLPA's mutual decision to modify the concussion protocol evaluation. The specifics have not yet been announced.
Follow USA TODAY Sports' Tyler Dragon on Twitter @TheTylerDragon.
This article originally appeared on USA TODAY: NFL Week 4 analysis: Cowboys on top; Dolphins fail Tua Tagovailoa