The old adage in the NFL is that you don’t judge a draft class until three or four years down the road. Generally, I agree with that point of view.

But there are exceptions. Take the quarterback draft class of 2018. Two years into it, you can look at the five quarterbacks taken in the first round and make some firm judgments. Overall, teams got it wrong.

It turns out the best quarterback from that draft was the fifth one taken and the last player taken in the first round. That’s Baltimore’s Lamar Jackson. The first quarterback – and first overall pick – was Baker Mayfield by the Cleveland Browns. He hasn’t turned out to be what people thought he would.

Think the Browns would take Jackson with the first pick if they had the chance to do it all over again? Of course they would. Hindsight is 20/20 and the entire order of 2018 quarterbacks probably would be different if teams could do that draft over again.

With the help of an NFC scout who spoke on the condition of anonymity, let’s review the thinking on each of the five first-round quarterbacks from 2018 — both when they came into the league, and how they’re viewed after two seasons.

Baker Mayfield, Cleveland Browns

Mayfield was the No. 1 overall selection out of Oklahoma. Despite the fact that some viewed Mayfield’s height (6-foot-1) and demeanor as potential problems, he was the consensus top pick.

“I was at one of his practices and I wasn’t all that impressed with him,’’ the scout said. “Yeah, he can throw the ball. But he has an outspoken vibe. Everybody else was in pads, but he was running around in sweats with a sweat band on his head. He reminded me of Jim McMahon and not a guy you would take at No. 1.’’

Mayfield looked like a No. 1 pick at times as a rookie, completing 63.8% of his passes and setting an NFL rookie record with 27 touchdown passes. Mayfield was intercepted 14 times as a rookie.

But Mayfield regressed in 2019 despite the arrival of receiver Odell Beckham Jr. He completed only 59.4% of his passes with 22 touchdowns and 21 interceptions.

“He’s just really inconsistent,’’ the scout said. “His height was a big factor this year. They had protection problems. When you’re shorter and you have protection problems, it’s tough to get the ball out. Not everybody is Drew Brees or Russell Wilson. I’m also real curious to see how the new coach handles his personality.’’