The Carolina Panthers and Arizona Cardinals were the two most successful teams during the NFL’s 2015 regular season. Carolina posted the league’s best-record, at 15-1, and led the league in scoring margin (+192). Arizona had the second-best record in the NFL (13-3) and finished with the second-best margin (+176). Carolina’s quarterback, Cam Newton, was selected as the league’s most valuable player and the first-team All-Pro quarterback by the Associated Press, while Arizona’s quarterback, Carson Palmer, received the second-most votes for that All-Pro slot.

The two teams met in the NFC championship game, with Carolina winning in a blowout, 49-15. And, of course, the Denver Broncos upset Carolina in the Super Bowl. But ugly performances by Carolina and Arizona in their final games of the 2015 season didn’t temper preseason expectations: NFL.com’s preseason power rankings had the Panthers and the Cardinals as its top two teams. But with both teams starting the 2016 season with a 1-3 record, is it time for panic?

How we got here

The Panthers and Cardinals have followed remarkably similar paths to 1-3:

Week 1: wide left

Each team lost to its counterpart from the 2015 AFC championship game in Week 1, and both games were defined by last-minute missed field goals. Carolina lost to Denver, 21-20; the game was decided when Graham Gano’s 50-yard field-goal attempt went wide left. Arizona lost to New England, 23-21, as Cardinals kicker Chandler Catanzaro’s 47-yard attempt went wide left in the final minute, preserving the win for the Patriots.

Week 2: the correction

Both teams had blowout victories in Week 2. Carolina scored a league-high 46 points in its win against San Francisco, while Arizona won 40-7 against Tampa Bay. That 33-point difference was the largest margin of victory of any team so far this season.

Week 3: double-digit losses as favorites

The Cardinals lost on the road, 33-18, to a Buffalo team that Arizona was favored to beat by 5 points. The Panthers lost at home, 22-10, to a Vikings team that Carolina was favored to beat by 6 points. For both teams, special teams touchdowns and interceptions (Palmer threw four, Newton had three) were the stories of the day.

Week 4: division rivals and quarterback concussions

A 1-2 start isn’t cause for panic, but that fourth game is pivotal: Since 1990, 2-2 teams have finished, on average, with 8.0 wins, while 1-3 teams have averaged only 6.2 wins. And with both Carolina and Arizona facing division rivals that were 2-1, a loss would have dropped them two games (and a tiebreaker) out of the division lead.

Carolina lost to Atlanta 48-33, while Arizona was shocked by the Rams 17-13. To add injury to insult, both star quarterbacks left the game in the fourth quarter, leaving their short-term future in doubt. Newton entered the concussion protocol after taking a hit from Falcons linebacker Deion Jones on a 2-point conversion; Newton did not return. Palmer also entered the concussion protocol after taking a hard hit in the fourth quarter of his team’s loss; he didn’t return, either, and his status is in doubt for Thursday’s game against the 49ers.

Historical context

From the AFL-NFL merger in 1970 through 2014, 180 teams made it to the AFC or NFC championship game. On average, those 180 teams won 2.6 of their first four games the following season. The table below shows how those teams fared the year after playing in a conference championship game, based on their number of wins through four games and over the remainder of the season. Arizona and Carolina are now the 19th and 20th teams to start 1-3 after playing in a conference championship game.

RECORD NUMBER OF TEAMS REST-OF-SEASON WINNING PCT. 0-4 5 – 52.6% 1-3 18 – 50.6 2-2 51 – 59.6 3-1 71 – 66.2 4-0 33 – 68.9 Teams that played in a conference championship game the previous season, through four games and the rest of the year For the period from 1970 to 2014 Source: Pro-football-reference.com

Even among this sample of teams that had been very successful the previous year, a 1-3 start puts a team in a huge hole: We would project a 1-3 team to finish with a 7-9 record based on these results. And of the 18 teams that started 1-3 after making the conference championship game the previous year, only three made the playoffs: the 1976 Steelers, the 1996 Cowboys and the 2002 Steelers.

The Cardinals can get it together, but they better hurry

While the Panthers and Cardinals had the two best quarterbacks in the NFL last year, neither team was one-dimensional. Carolina finished in the top two in both rushing yards and yards per carry, while the Cardinals running backs finished third in yards per carry and second in rushing yards among running back units. In addition, both teams sported top defenses.

This year? Well, neither Palmer nor Newton is playing well, ranking 23rd and 24th, respectively, according to ESPN’s Total Quarterback Rating (QBR). And for both teams, there is no shortage of blame to spread around. The table below shows Arizona’s Expected Points Added — which measures the increase in expected points by a team from one play to the next — from the offense, defense and special teams in each week.

EXPECTED POINTS ADDED BY … WEEK OPPONENT RESULT SCORE OFFENSE DEFENSE SPECIAL TEAMS 1 Patriots L 21-23 +11.2 -4.5 -9.1 2 Buccaneers W 40-7 +14.5 +17.9 +0.6 3 Bills L 18-33 -19.6 +1.3 +3.3 4 Rams L 13-17 -4.3 +3.6 -3.3 The Cardinals had one excellent game and three mediocre ones Source: ESPN’s Stats & Information Group

Arizona can still make the playoffs even with average quarterback play, thanks to a talented supporting cast, but the Cardinals won’t be a Super Bowl contender unless Palmer can play like he did for most of 2015. But with a chance that Drew Stanton, not Palmer, will be playing Thursday night as the Cardinals try to dig out of their 1-3 hole, it’s probably time to panic.

The Panthers might be screwed

In Carolina, things look bleaker. The table below shows the EPA by unit for the Panthers in each game they’ve played this year:

EXPECTED POINTS ADDED BY … WEEK OPPONENT RESULT SCORE OFFENSE DEFENSE SPECIAL TEAMS 1 Broncos L 20-21 +3.9 -2.9 -1.5 2 49ers W 46-27 +8.6 +14.8 -4.0 3 Vikings L 10-22 -13.0 +5.7 -5.2 4 Falcons L 33-48 +4.5 -21.1 +2.6 The Panthers have been inconsistent Source: ESPN’s Stats & Information Group

The Carolina offense was unusually successful last year: The Panthers led the NFL in scoring and offensive touchdowns, but the team ranked just 11th overall in yards and just ninth in net yards per pass. Carolina also averaged a league-high 5.54 points per trip to the red zone last season, and history shows that that level of success isn’t sustainable; as a result, some regression to the mean on the scoreboard was to be expected.

But the defense, which returned All-Pro linebackers Luke Kuechly and Thomas Davis and Pro Bowl defensive tackle Kawann Short, was supposed to again be among the league’s stingiest units. So far, it has allowed Trevor Siemian to lead a fourth-quarter comeback in his first NFL start, failed to record a takeaway against a Vikings team missing Adrian Peterson and in Sam Bradford’s second start with the team, and on Sunday allowed an opposing QB to reach 500 passing yards and an opposing pass catcher to reach 300 receiving yards in the same game, a first in the Super Bowl era.

Josh Norman isn’t walking through that door, and both Newton and Davis (hamstring) are banged up. The Panthers were probably worse than their record for most of last year and are likely better than their record this year. But with both the offense and defense taking steps back, it’s time to panic in Carolina.

CORRECTION (Oct. 4, 1 p.m.): An earlier version of a chart in this article gave the incorrect record after four games for a group of 33 NFL teams that had reached the conference championship game the year before and went on to win 68.9 percent of their remaining games. Their record was 4-0, not 4-4.