Best Year 2 quarterback breakout seasons in NFL history: Could Trevor Lawrence, Zach Wilson, Trey Lance, Justin Fields, Mac Jones match?

Five quarterbacks were drafted in the first round of the 2021 NFL draft. Four of them -- Trevor Lawrence (Jaguars), Zach Wilson (Jets), Justin Fields (Bears) and Mac Jones (Patriots) -- saw significant time as rookies. Trey Lance (49ers) had only a couple of spot starts, but third-round pick Davis Mills eventually won a starting job with the Texans. In all, just over 12% of the pass attempts we saw in regular-season games last season were thrown by rookies.

Those quarterbacks weren't very good. Out of 31 qualifying passers, four of the five first-round rookies ranked 26th or worse in Total QBR. Jones was the only one who wasn't in the bottom six; he finished 16th in the league. Lance didn't play frequently enough to qualify, but it's clear this group of would-be standouts expects to take a step forward in 2022.

The good news for fans of these young passers is the Year 2 breakout practically has turned into an obligation. Over the past five seasons, we've seen two second-year passers win MVP awards, while a third was denied only by an injury. Another made the single largest leap we've ever seen from a second-year quarterback, while a fifth came within one drive of winning Super Bowl LVI.

With six sophomore quarterbacks expected to serve as their team's starter heading into 2022, which one(s) will break out? To try to answer that question, I looked at notable Year 2 breakouts from years past to get a sense of what those quarterbacks looked like after their first seasons.

Comparing quarterbacks across eras isn't foolproof, and with passing stats at all-time highs, we need to measure players against their competitors as opposed to simply using raw stats. With that in mind, to contextualize passing performance, I'm using an indexed metric from Pro Football Reference called adjusted net yards per attempt (ANY/A+).

A better version of passer rating, ANY/A uses more accurate weights for touchdowns and interceptions while also incorporating yards lost on sacks. Then, the indexing places the stat on an easy-to-understand scale, making it so that a 100 ANY/A+ is a league-average performance in any given season. That means 115 would be a good season, and 130 would be an incredible campaign; likewise, an 85 ANY/A+ would be disappointing, while a 70 ANY/A+ would be a disaster.

I'll hit eight second-year breakouts, going back nearly 40 years in the process. To start, let's begin with one of the most dramatic second-year campaigns in league history:

Jump to a Year 2 breakout comp:
Brady | Burrow | Foles | Goff
Jackson | Mahomes | Marino | Wentz

Patrick Mahomes, Kansas City Chiefs: 2018

The story: Raw prospect takes a year to develop on the bench under an offensive genius before breaking out.

It seems bizarre to consider now, but there was a time when Mahomes wasn't regarded as a preternatural quarterback prospect, let alone as one of the best players on the planet. Opinions were mixed on him heading into the 2017 draft. The Bears famously chose Mitch Trubisky ahead of the future Hall of Famer, and in Bob McGinn's poll of NFL scouts and executives before the draft, Mahomes was ranked third among quarterbacks, behind Trubisky and Deshaun Watson.

The Chiefs traded up for Mahomes and took him with the No. 10 overall pick, but with Alex Smith entrenched as their starter, coach Andy Reid & Co. didn't rush the Texas Tech star into the lineup. Smith led the league in passer rating (104.7) and ranked second in yards per attempt (8.0), and the Chiefs left Mahomes on the bench for nearly all of his rookie season. The only game action he saw was in Week 17, when he played in what amounted to a JV game against the Broncos, throwing for 284 yards with an interception.

After clearing out a starting spot by trading Smith to Washington, the Chiefs installed Mahomes as their starter in 2018. Mahomes had the league's best group of playmakers, but no one could have quite imagined what happened next.

Mahomes was a superstar by the end of September, as he threw for 896 yards and 13 touchdowns without an interception over his first three games. He finished the season with 5,097 passing yards and 50 touchdown throws, joining Peyton Manning as the second quarterback in league history to join the 5,000 and 50 club. Mahomes' 136 ANY/A+ ranks as the 20th-best single-season mark in league history.