They say it takes three years to truly evaluate an NFL draft class, but the New Orleans Saints shifted that process into hyperdrive last season with one of the best rookie hauls in league history.

Running back Alvin Kamara and cornerback Marshon Lattimore became the first duo to sweep the league's Offensive and Defensive Rookie of the Year awards in 50 years, with both making the Pro Bowl. A total of five rookies became starters for the Saints, including offensive tackle Ryan Ramczyk and safety Marcus Williams, who looked like potential Pro Bowlers.

As a result, the Saints ended a three-year playoff drought and came one play away from the NFC Championship Game. Now they have soared a staggering 22 spots in ESPN's Future NFL Power Rankings -- from No. 25 at this time last summer to No. 3.

A year ago, ESPN's group of insiders expressed concerns about then-38-year-old quarterback Drew Brees heading into the final year of his contract and New Orleans' roster being full of holes.

Now, Brees has re-upped for two more years and the Saints suddenly have one of the league's most balanced rosters after landing seven players in the Pro Bowl.

So what can they do for an encore?

Kamara, Lattimore and third-year star receiver Michael Thomas all insisted they won't rest on their laurels -- that they want to accomplish even more this season, be ranked among the all-time greats and "legends" of the game while leading New Orleans back to a Super Bowl. All three have certainly flashed the talent to do so.

But what does history tell us about how rookie classes like this have fared?

ESPN Stats & Information dug up the six best draft classes since the NFL went to the current seven-round format in 1994, based on Pro Football Reference's "approximate value" rating it assigns to every player in the NFL. It's an inexact measure, but it's the best way to compare players across all position groups and eras.

Here's how they rank, according to the total first-year AV of each class:

This lofty ranking is all about the two breakout stars, Dak Prescott and Ezekiel Elliott, who burst onto the scene and led Dallas to a 13-3 record and the NFC's No. 1 seed before losing in the divisional round of the playoffs. But the jury is still out on this group after the Cowboys fell to 9-7 last season and missed the playoffs -- largely because of Elliott's six-game suspension for violating the league's personal-conduct policy. Prescott's performance also dropped off slightly (he went from four interceptions in 2016 to 13 in 2017). But the future obviously remains bright for both. Maliek Collins and Anthony Brown had similar production as contributors in Year 2.

Who better than the Browns to provide the ultimate cautionary tale? This group had a total AV of 57 among all rookies (including undrafted standouts such as LB Craig Robertson and DB Tashaun Gipson). Nevertheless, they crashed and burned at an astonishing rate, going from five wins in 2012 to 4, 7, 3, 1 and 0 over the next five years through multiple regime changes. Brandon Weeden started 15 games as a rookie with a 5-10 record, but was released after going 0-5 the next season. Trent Richardson ran for 946 yards and 11 touchdowns as a rookie, but was traded two games into the next season and has since flamed out. Josh Gordon was sensational as a sophomore, leading the NFL with 1,646 receiving yards in 2013. But he went on to miss a whopping total of 56 games because of suspension while battling drug and alcohol issues before finally being reinstated late last season. Only Mitchell Schwartz has been a solid starter throughout his career -- but he bolted for Kansas City as soon as he became a free agent.

Kamara's rookie season was astonishing -- especially considering he was a third-round pick from Tennessee who was expected to play a part-time role alongside veterans Mark Ingram and Adrian Peterson. Kamara wound up setting the NFL record for most yards per offensive touch (7.7) among players with at least 200 touches in a season. And he joined Gale Sayers as the only two rookies with at least five rushing touchdowns, five receiving TDs and a kickoff-return TD. Lattimore was just as valuable, emerging as a desperately needed No. 1 cornerback to spark the Saints' remarkable resurgence on defense. His AV seems way too low -- though it might be a result of teams being afraid to throw his way. Ramczyk was expected to learn behind veteran Zach Strief in 2016, but wound up playing every snap because of injuries for an offense that led the NFL in yards per rush and yards per pass attempt. Williams was also vital to New Orleans' defensive turnaround, with five interceptions including the playoffs, before his infamous missed tackle in the "Minnesota Miracle."

Jimmy Johnson is known for turning around the Cowboys in the late '80s and early '90s. But his first draft class as coach of the Dolphins in 1996 wasn't too shabby. Zach Thomas (a fifth-round pick) became a seven-time Pro Bowler and one of the leading tacklers in NFL history, with more than 1,600 in 13 seasons. Karim Abdul-Jabbar had nearly 3,500 yards from scrimmage and 33 touchdowns in three seasons before his career fizzled. Daryl Gardener was a solid starter for the better part of six years. And the Dolphins also landed all-time great special-teams ace Larry Izzo and longtime NFL kicker Joe Nedney as undrafted free agents. This group had a good run – the Dolphins went 8-8 in '96, followed by five consecutive playoff appearances and seven straight winning seasons as they transitioned from QB Dan Marino to QB Jay Fiedler. Alas, they never made it past the divisional round of the playoffs (and still haven't to this day).

Now, this class was a true game-changer. Seattle went 11-5 in 2012, then went 13-3 and won the first Super Bowl in franchise history a year later. This class helped lead the Seahawks to five straight playoff appearances and six straight winning seasons. Russell Wilson, a third-round pick, and Bobby Wagner, a second-rounder, have become two of the best players in the NFL at their respective positions. They have both earned four Pro Bowl selections, and Wagner is a three-time first-team All-Pro. Bruce Irvin and J.R. Sweezy also became full-time starters.

This almost seems unfair, doesn't it? The Patriots had already won three Super Bowls in the Bill Belichick-Tom Brady era before they reloaded in the middle of their dynasty with an all-time great draft class. Rob Gronkowski, a second-round pick, has become arguably the most dominant tight end in NFL history. And Devin McCourty has been key to New England's success as an eight-year starter and two-time Pro Bowler. Aaron Hernandez was a big part of the Patriots' offense for two-plus years before his stunning fall from grace as a convicted murderer (the charge was thrown out after he died in prison). And Brandon Spikes was a four-year starter. The Patriots went 14-2 in 2010 before losing in the divisional round of the playoffs. They have won at least 12 games every season since, with three more trips to the Super Bowl and one title win.