Gauging success and failure in the NFL is actually quite easy. Teams either take the field and winor they lose.

On Sunday, Cleveland Browns head coach Mike Pettine said the NFL is a “pass/fail league,” and that his team failed.

Well, the Browns failed to get the win. But let’s see how the Browns and the other 31 NFL teams would do if the NFL wasn’t a pass/fail league by assigning letter grades for their Week 1 performances.

Week 1 NFL report cards are in.

Seattle Seahawks (W, GB, 36-16)

It’s almost unfair that after winning the Super Bowl last season, the Seahawks get a weapon on offense that they didn’t have for 15 games in 2013. Percy Harvin accounted for 120 all-purpose yards, catching seven passes for 59 yards, running for 41 yards and returning kickoffs for 20 yards. Seattle held Green Bay to 255 yards of offense, including 80 on the ground.  If Aaron Rodgers is afraid to throw the ball anywhere near Richard Sherman, who will throw at him? And Pete Carroll’s not at USC anymore. He’s not exactly feasting on the Hawaii of the NFL for an easy early-season win. The Packers could be back at CenturyLink Field in January for a rematch.

Grade: A

Minnesota Vikings (W, at STL, 34-6)

Cordarrelle Patterson didn’t disappoint all the fantasy football pundits expecting a breakout season from him. He needed just three carries to run for 102 yards, 27 more than Adrian Peterson. The Minnesota Vikings weren’t nearly as touted in real football as Patterson was in fantasy, but they provided a pleasant surprise for their fans in Mike Zimmer’s head coaching debut. The Rams might have been third in the NFL with 53 sacks last season, but it was actually the Vikings harassing Rams quarterbacks with five sacks. The Vikings also intercepted two passes and forced four fumbles.

Grade: A

Miami Dolphins (W, NE, 33-20)

Knowshon Moreno must love playing against the Patriots. He’s run for 358 yards combined in his last two regular-season games against them, including 134 yards and a fourth-quarter touchdown Sunday that gave the Dolphins a 30-20 lead. The offensive line, without Mike Pouncey, allowed Ryan Tannehill to be sacked just once. Mike Wallace earned his money with seven catches for 81 yards and the game-tying touchdown in the third quarter. The Dolphins out-scored the Patriots 23-0 in the second half of this milestone win for the franchise.

Grade: A-

San Francisco 49ers (W, at DAL, 28-17)

No NaVorro Bowman. No Aldon Smith. No problem for the 49ers. Cornerback Chris Culliver returned a DeMarco Murray fumble 35 yards for a touchdown on the second play of the game. After the 49ers increased their lead to 14-3 in the first quarter, safety Eric Reid intercepted Tony Romo and returned it 48 yards to the Cowboys’ 2-yard line. Colin Kaepernick threw his second touchdown pass to Vernon Davis on the next play, and the game was pretty much over at that point. Perrish Cox added an interception and Justin Smith had two sacks. The 49ers will face sterner defenses, but for now they look OK.

Grade: A-

Buffalo Bills (W, at CHI, 23-20, OT)

This was the upset of the week. The Bills were supposed to finish with one of the worst records in the NFL. The Bears, on the other hand, were supposed to become an offensive juggernaut with Jay Cutler playing his second year in Marc Trestman’s system. What actually happened was the Bills gobbled up 193 rushing yards at an average of 5.8 yards per carry. The wealth was spread among Fred Jackson (61 yards), Anthony Dixon (60 yards) and C.J. Spiller (53 yards). E.J. Manuel wasn’t spectacular. But he was an efficient 16-of-22.

Grade: A-

Cincinnati Bengals (W, at BAL, 23-16)

The Bengals showed some grit after blowing a 15-0 lead and falling behind 16-15 with six minutes left in the fourth quarter. It took less than a minute for them to regain the lead on Andy Dalton’s 77-yard touchdown pass to A.J. Green. They stopped the Ravens on their last possession to seal their first victory at Baltimore since 2009. Dalton threw for 301 yards and wasn’t sacked. By the way, had anyone heard of Emmanuel Lamur heading into the season? Well, he led the Bengals with 11 tackles and had an interception in the third quarter.

Grade: A-

Houston Texans (W, WAS, 17-6)

The Texans had contributions from their offense, defense and special teams in winning their first game in almost a year. DeAndre Hopkins caught a 76-yard touchdown pass from Ryan Fitzpatrick to give Houston a 7-6 lead in the second quarter. After the ensuing three-and-out, rookie Alfred Blue blocked a punt and returned it for a touchdown. J.J. Watt, the Texans’ $100 million man, had a sack, made two tackles for losses, batted down a pass, blocked an extra point and hit Robert Griffin III five times. Other than that, Watt didn’t do much (!).

Grade: A-

Arizona Cardinals (W, SD, 18-17)

Coming back from fourth-quarter deficits is something the Cardinals will have to do from time to time to keep up with Seattle and San Francisco in the NFC West. The Cardinals mustered just six points in the first three quarters, but 34-year-old Carson Palmer rose to the occasion in the final stanza for his 17th career fourth-quarter comeback. He threw a five-yard touchdown pass to Stepfan Taylor to pull the Cards to within 17-12 with 12:30 to go and found rookie John Brown on a screen pass with 2:25 left. The third-round draft pick did the rest and dodged defenders all the way into the end zone. Palmer threw for 304 yards on the evening.

Grade: B+

Carolina Panthers (W, at TB, 20-14)

On the road against a team that spent a lot of money on its defense in free agency, the Panthers had more question marks at wide receiver than there are on The Riddler’s costume. Not only that, but journeyman backup quarterback Derek Anderson was replacing an injured Cam Newton. Rookie Kelvin Benjamin (eight catches, 92 yards, touchdown) and veteran Jerricho Cotchery (four catches, 32 yards) went a long way toward answering the questions at receiver, and Anderson completed 24 of 34 passes for 230 yards and no interceptions. Even if a quarterback controversy is brewing, it’s a good problem for the Panthers to have.

Grade: B+

Tennessee Titans (W, at KC, 26-10)

This was another game that wasn’t as close as the final score indicated. The Titans led 23-3 in the fourth quarter. Ryan Succop made all four of his field-goal attempts after being cut by the Chiefs. Jake Locker completed 22 of his 33 passes for 266 yards and a touchdown. If Ken Whisenhunt can work his offensive wizardry on Locker, it would be his biggest coaching masterpiece. The Titans intercepted Alex Smith three times and sacked him four times, but they also allowed four sacks and overcame 12 penalties. It’s too early to get excited about the Titans, though. They looked like they were on the way up after winning at Pittsburgh in last year’s opener.

Grade: B+

Atlanta Falcons (W, NO, 37-34, OT)

The Falcons picked a thrilling way to make their fans forget about last year’s 4-12 season. They came back from deficits of 13-0 and 20-7 in the first half. Then they fell behind 34-31 with 1:20 left, but forced overtime on Matt Bryant’s 51-yard field goal. Bryant won it with a 52-yarder in overtime. Matt Ryan threw for a franchise-record 448 yards and the Falcons generated 568 yards of total offense. Their defense left something to be desired, allowing 472 yards and eight of 13 third-down conversions. But they get a pass on that considering the opponent.

Grade: B

Detroit Lions (W, NYG, 35-14)

When the Lions do what they did Monday against a more imposing opponent, they’ll get strong consideration for an “A.” But a solid “B” is fine for now. The secondary, which had been the biggest trouble spot on the Lions defense, came through Monday night. Safety Glover Quin had an interception and second-year cornerback Darius Slay broke up three passes as the Lions held the Giants to 197 yards of offense. Detroit’s offense didn’t disappoint. Matthew Stafford threw for 346 yards and a pair of touchdowns and the Lions moved the chains on 10 of their 15 third downs.

Grade: B

Denver Broncos (W, IND, 31-24)

The Broncos dominated the first half with their offense, and in the second half their re-tooled defense stopped the Colts when it had to. Peyton Manning threw three touchdown passes to tight end Julius Thomas in the second quarter to give the Broncos a 24-0 lead. Denver still led 31-10 in the fourth quarter, but its offense generally stalled in the second half. That allowed the Colts to get back into the game, but Rahim Moore made one of his two interceptions in the fourth quarter. Then, with just under two minutes left, rookie cornerback Bradley Roby broke up a pass to seal the victory for the Broncos. DeMarcus Ware had 1.5 sacks in his Broncos debut.

Grade: B

Green Bay Packers (L, at SEA, 36-16)

The Packers will be graded on a curve because they went up against the defending Super Bowl champions in the Thursday night season opener. The tradition of Super Bowl champions starting the following season’s opener on Thursday night began in 2004. The defending champ has lost that game only twice. One of those times was last season when the Ravens had to play the game at Denver. It’s difficult enough facing the NFL’s reigning champs in the league’s toughest stadium for road teams, but add a healthy Percy Harvin (team-high seven catches for 59 yards), and it’s a task that is much more difficult. The Packers will be fine when they face mere mortals.

Grade: B- 

New York Jets (W, OAK, 19-14)

It was Chris Ivory, not Chris Johnson, breaking the 100-yard mark for the Jets. He ran the rock 10 times for 102 yards while Johnson added 68 yards on 13 carries as the Jets amassed 212 rushing yards as a team. Ivory chalked up 71 of his yards on a touchdown run in the fourth quarter, increasing the Jets’ lead to 19-7 with eight minutes left. Raiders’ rookie quarterback Derek Carr completed 20 of 32 passes with two touchdowns and no interceptions. The Jets’ suspect secondary has to be ready to face better quarterbacks (like Aaron Rodgers in Week 2).

Grade: B-

Indianapolis Colts (L, at DEN, 31-24)

The Colts weathered the early storm and made a game of it in the second half. They couldn’t complete the comeback, but they performed admirably in prime time on the road against the defending conference champions. Andrew Luck threw for 370 yards, even if it took 53 passes (with 35 completions) to get there. Luck endured three sacks but threw two touchdown passes in the fourth quarter after the Colts fell behind 31-10. The Colts didn’t have many opportunities to run the ball after falling so far behind, but Trent Richardson could only gain 20 yards on his six carries.

Grade: B-