Jets rookie quarterback Sam Darnold walks off the field after...

Jets rookie quarterback Sam Darnold walks off the field after the 20-12 loss to the Miami Dolphins at MetLife Stadium on Sunday. Credit: Kathleen Malone-Van Dyke

What a Jet letdown.

This is nothing new, and it probably was predictable considering the history of this team. Never get too high, right, Jets fans?

But it was supposed to be a new era with Sam Darnold now running the Jets. Their inspiring Week 1 victory in Detroit was supposed to be a springboard for a team heading in a different direction. It turned out to be wishful thinking, as many of the nearly 78,000 fans left MetLife Stadium on Sunday with that all too familiar taste of disappointment and frustration after the Jets lost their home opener, 20-12, to the Dolphins.

And it was some of the same old issues that popped up and cost the Jets on an afternoon when Darnold recorded the first of what should be many 300-yard passing games.

They committed three turnovers, two on Darnold interceptions, had two defensive holding penalties negating third-down sacks and had trouble finding the end zone all game.

“It’s very disappointing,” Quincy Enunwa said. “Lack of execution, penalties, and then turnovers. Honestly, we beat ourselves. I’m pretty sure we out-[gained] them. We kind of gave the game away. It’s frustrating.”

The Jets held the advantage in total yards (362-257) and in time of possession, by nearly three minutes.

You don’t want to say same old Jets after this deflating loss to their AFC East rival. But if you did, it would be justified after a game that had so many features that reminded everyone why it’s been so long since this team has been in the playoffs, never mind a Super Bowl.

“Nobody played well, nobody coached well,” Todd Bowles said.

The Dolphins (2-0) led 20-0 after a very sloppy and mistake-filled first half by the Jets that had what probably was a fitting ending.

The Jets had a chance to score right before the second quarter ended, but the drive stalled on the 1-yard line. Rookie Chris Herndon couldn’t get in the end zone on a short pass across the middle and time ran out because the Jets were out of timeouts. On the play before, Darnold overthrew Quincy Enunwa, who was wide open in the end zone. Darnold was trying to throw it away to stop the clock and didn’t see Enunwa until the last second.

In the fourth quarter, there were also back-to-back false starts in Dolphins territory on a critical drive. The Jets had to settle for a field goal.

The Jets’ defense was their best unit, as they suddenly had a pass rush. They sacked Ryan Tannehill four times, and it would have been six if not for penalties at key moments. They also gave up a 19-yard pass play to running back Frank Gore on third-and-19 late in the fourth quarter that put the game away.

“Somebody missed a pick-up,” Bowles said.

Darnold had some good moments, but he was not sharp overall -- 25-for-41 for 334 yards, one touchdown and two interceptions.

The rookie completed his first pass this game, but he was picked off on the Jets’ second series. He made a bad decision on a pass to Enunwa and was intercepted by T.J. McDonald, who returned it 31 yards, leading to Miami’s first touchdown.

“I didn’t see him,” Darnold said.

Darnold also threw a pick in the end zone in the third quarter after momentum seemed to be swinging in the Jets’ favor.

Running back Bilal Powell scored on a 28-yard pass from Darnold to open the third quarter. The defense forced a turnover 13 seconds later, when a big sack and fumble recovery by Jordan Jenkins gave the Jets the ball on the Miami 12. But Xavien Howard picked off Darnold in the end zone on the next play on a pass intended for Terrelle Pryor.

“We were on the same page,” Darnold said. “Just have to execute a little better.”

The defense continued to do its job and the offense continued to sputter.

The Jets got into Miami territory on their first two fourth-quarter drives but ended up with Jason Myers’ field goals of 55 and 41 yards. The latter made it 20-12 with 5:56 left. The Jets needed a big stop on the next series, but they couldn’t get it.

After two straight tackles for losses, they had Miami facing a third-and-long from the Jets’ 43. But Tannehill dumped it off to the ageless Gore, who scurried 19 yards for the first down with 2:49 to go. The Jets never got the ball back.

“The whole game was pretty frustrating,” defensive end Leonard Williams said. “They were making some big plays that I didn’t like. We were getting some penalties in clutch situations that I didn’t like.”

The Jets have to put this game behind them quickly. It’s a very short week. They play Thursday night in Cleveland, closing out their season-opening stretch of three games in 11 days.

The way the Dolphins jumped out to the big lead was disturbing for the Jets. Darnold’s interception on the second drive led to a 6-yard Kenyan Drake touchdown run. Three series later, Robby Anderson fumbled after a 10-yard gain, giving the ball to the Dolphins at the Jets’ 49.

Nickel corner Buster Skrine had a rough series. He committed a 15-yard face-mask penalty on the first play. On the next, Albert Wilson took a short cross and went 29 yards for the touchdown after Skrine dove but failed to make the ankle tackle.

On the next series, the Jets got to Tannehill for the third time in the half. Williams and Williamson brought Tannehill to the turf on third-and-6, which would have knocked the Dolphins out of field-goal range, but corner Mo Claiborne was whistled for holding. Two plays later, Tannehill connected on a 19-yard touchdown with tight end A.J. Derby for the 20-0 lead.

“I’m disappointed about the loss,” Williams said. “First home game, we came off of a big win last week and we wanted to keep staying consistent. Overall, I’m not disappointed in my team. Nobody is walking around moping and acting like this is the end of the world. There is a long road ahead of us.”

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