Last week, the Indy stars became the first rookie duo to make the first-team All-Pro roster since 1965. Could the two be the best first-year pairing in league history?

Last Friday, the Indianapolis Colts made history. That day linebacker Darius Leonard and guard Quenton Nelson were named to the 2018 Associated Press All-Pro first team, making them the first pair of rookie teammates to earn first-team All-Pro honors in more than 50 years; Gale Sayers and Dick Butkus were the last to do it with the Bears in 1965. A day later, the Colts upset the Texans 21-7 in the wild-card round and punched their ticket to a divisional round matchup against the Chiefs.

All season, Leonard and Nelson have helped propel the Colts well beyond their preseason expectations. Indianapolis was projected to finish toward the bottom of the league in 2018 by various outlets, including NFL.com, which ranked them 32nd heading into the season. Instead, Indy has used that as motivation. And after a 1-5 start, the Colts went on a tear. They lost just one game the rest of the season, thanks to a resurgent Andrew Luck, Frank Reich’s modern offense, the surprisingly sturdy play of the defense, and, of course, Leonard and Nelson.

Leonard led the NFL in both solo and combined tackles this season and had 7.0 sacks, four forced fumbles, and two interceptions. He was everywhere for the Colts, solidifying the middle of their defense and earning Pro Football Focus’s ninth-highest grade for a linebacker. Meanwhile, Nelson anchored the interior of the Colts offensive line. He helped protect Luck, who was sacked on a league-low 2.7 percent of his dropbacks, and opened running lanes for Marlon Mack, Nyheim Hines, and the rest of the Colts rushers. Nelson earned PFF’s fourth-highest grade for a guard, and the only lowlight of his season was that this viral video of him screaming while making a soul-wrecking block …

… turned out to be fake.

Nelson won’t earn the Offensive Rookie of the Year award, as that race seems to be a dead heat between Baker Mayfield and Saquon Barkley, but Leonard is the betting favorite for the defensive trophy. That hardware would be a nice consolation prize for Leonard, considering he was left off the Pro Bowl roster (though he is an alternate and could make the roster if one of the linebackers ahead of him declines to attend).

Leonard and Nelson have been so good that it’s time to ask: Are they the best rookie duo of all time?

To help answer that question, we can turn to Pro-Football-Reference’s approximate value metric, which is PFR founder Doug Drinen’s attempt to attach a numerical value to each player across each season of their career. AV goes back to 1960, and while it has its flaws, it is one of the best methods we have for quantifying a player’s contribution in a given season. With those numbers in hand, we can look at the AV rookie players have earned across NFL history, combine the top teammates, and rank them.

But before we do that, there is a quick caveat: Simply combining players’ AV leaves us vulnerable to an issue that I’ll call the Edgerrin James Effect. James’s 1999 season carried an AV of 21—the highest ever for any rookie. Combining that figure with rookie receiver Terrence Wilkins’s AV of nine, which is a pretty forgettable number, would give the 1999 Colts the fourth-best rookie duo of all time. But James and Wilkins weren’t really a “duo”—James was just so great that pairing any halfway decent rookie alongside him would send them to the top of this leaderboard. To account for that, we’re only ranking duos where both members recorded at least 10 AV. Double digits or bust.

So with that in mind, here’s where Leonard and Nelson fall within the top 10 rookie duos of in NFL history:

T-9. RB Alvin Kamara and OT Ryan Ramczyk, 2017 New Orleans Saints (25 combined AV)

This duo presents a curious start to the list. The 2017 Saints draft class was a resounding coup for New Orleans and propelled a team that had gone 7-9 in three consecutive seasons to back-to-back playoff appearances. But if you were to guess which rookie duo from that squad was the most valuable, you’d probably pick Kamara and defensive back Marshon Lattimore. Kamara and Lattimore won the offensive and defensive Rookie of the Year awards, respectively, becoming the first pair of teammates to split those awards since Detroit’s Mel Farr and Lem Barney in 1967 (who would rank 11th in combined AV and just miss out on this list).

Yet Lattimore doesn’t do well by AV, coming in with just an eight, while Ramczyk earned a 10. Kamara, of course, was electric as a rookie, earning 15 AV as he picked up 1,554 scrimmage yards and 13 total touchdowns. Ramczyk started every game in 2017, paving the way for Kamara and earning Pro Football Focus’s 11th-highest rating for a tackle in the process.

If we were ranking rookie trios, these three would likely come in as the top group of all time—and the Saints may soon be raising a Lombardi trophy because of them.

T-9. RB Clinton Portis and G Ben Hamilton, 2002 Denver Broncos (25)

Portis’s Denver years were incredible, and as a rookie he picked up 1,872 scrimmage yards, tallied 17 touchdowns, and averaged a whopping 5.5 yards per carry in Mike Shanahan’s famous zone-blocking scheme. Portis won Offensive Rookie of the Year honors and missed out on the Pro Bowl only because 2002 was a banner season for AFC running backs: Priest Holmes, Ricky Williams, LaDainian Tomlinson, and Travis Henry all accounted for at least 1,700 yards and 14 touchdowns that year (Portis probably should have made the Pro Bowl instead of Henry, but it wasn’t an egregious snub). Hamilton helped Portis pick up all those yards as he started all 16 games in the interior of the offensive line.

T-7. QB Russell Wilson and LB Bobby Wagner, 2012 Seattle Seahawks (26)

Wilson instantly revitalized the Seahawks as a rookie. He won the starting job over pricey free-agent acquisition Matt Flynn in training camp, then took a team that had gone 7-9 in each of head coach Pete Carroll’s first two years to an 11-5 finish and the divisional round of the playoffs. Wilson lost out on the Offensive Rookie of the Year award to Robert Griffin III, but he threw for 3,118 yards, 26 touchdowns, and 10 interceptions while racking up a 100.0 passer rating and 7.01 adjusted net yards per attempt. It was one of the best rookie passing seasons ever.

Wagner wasn’t too shabby, either, starting 15 of 16 games and leading the team in tackles with 139 (an incredible 41 more than the next-highest Seahawk). He also picked off three passes, had two sacks, and became an immediate contributor to a defense that finished 2012 ranked no. 1 in points and no. 4 in yards allowed.

T-7. RB Boobie Clark and WR Isaac Curtis, 1973 Cincinnati Bengals (26)

Clark and Curtis were the focal points of Cincinnati’s offense as rookies. Clark tallied 1,335 yards from scrimmage and eight touchdowns while Curtis added 843 receiving yards and another nine scores. Curtis made the Pro Bowl that season and went on to have a 12-year career, though Clark never again reached the heights of his rookie season.

6. LB Lawrence Taylor and NT Bill Neill, 1981 New York Giants (27)

Taylor was a Pro Bowler and an All-Pro in his rookie year, though it’s hard to find out just how good he was as the NFL didn’t keep sack numbers until 1982 and tackle statistics until 1994. But the people who were around to actually watch him play knew he was a special talent: Taylor won both Defensive Rookie of the Year and Defensive Player of the Year honors that season.

Meanwhile, Bill Neill started all 16 games at nose tackle, and he and Taylor helped raise the Giants defense up from fifth-to-last in the league in yards and second-to-last in points allowed in 1980 to third in both categories in 1981.

5. RB Charley Taylor and S Paul Krause, 1964 Washington Redskins (28)

Taylor was a do-it-all player as a rookie, collecting 814 yards and five touchdowns through the air and another 755 yards and five touchdowns on the ground. He’d make a full-time switch to wide receiver in 1967, but in ’64 he was everywhere, and earned Pro Bowl honors while accounting for nearly 40 percent of Washington’s offensive yardage. On the other side of the ball, Krause was an All-Pro who recorded a league-leading 12 interceptions and another two fumble recoveries—and all of this was back when teams played only 14 games in a season.

T-3. QB Robert Griffin III and RB Alfred Morris, 2012 Washington Redskins (31)

RGIII’s career didn’t turn out the way Washington hoped, but his rookie season was undeniably special: He beat out both Wilson and Andrew Luck for the Offensive Rookie of the Year award. He also made the Pro Bowl while passing for 3,200 yards, 20 touchdowns, and just five interceptions—good for a 102.4 passer rating and 7.47 adjusted net yards per attempt.

Morris racked up 1,690 scrimmage yards and 13 total touchdowns, averaging 4.8 yards per carry in the same zone-blocking scheme that Portis found success with a decade earlier. Together, Griffin and Morris took an offense that ranked 16th in yards and 26th in points in 2011 to the top five in both categories in 2012. After winning five games the previous year, Washington finished 10-6 in 2012 before Griffin tragically tore his ACL in the wild-card round of the playoffs.

T-3. RB Gale Sayers and LB Dick Butkus, 1965 Chicago Bears (31)

Of course the last pair of rookie teammates to earn first-team All-Pro honors before Leonard and Nelson were incredible, and both Sayers and Butkus went on to become not only Hall of Famers, but true all-time greats. As a rookie, Sayers had 1,374 scrimmage yards and an unreal 20 touchdowns while averaging 5.2 yards per carry on the ground. And though we don’t have sack or tackle numbers for Butkus, he intercepted five passes and recovered seven fumbles that season.

2. QB Dak Prescott and RB Ezekiel Elliott, 2016 Dallas Cowboys (32)

It’s no surprise to see these two near the top of the list. Prescott had arguably the most successful rookie season for a quarterback in NFL history, with his adjusted net yards per attempt (7.86), passer rating (104.9), completion percentage (67.8), and interception rate (0.87) all ranking first all-time among rookie passers. Elliott led the NFL in rushing in 2016 and picked up 1,994 scrimmage yards and 16 total touchdowns. Both players made the Pro Bowl; Elliott was also named to the All-Pro team while Prescott took home the Offensive Rookie of the Year award.

Together, Prescott and Elliott (and a dominant offensive line) powered the Cowboys to a 13-3 season with an offense that ranked in the top five in both points and yards.

1. LB Darius Leonard and G Quenton Nelson, 2018 Indianapolis Colts (33)

Here you have it: By approximate value, Leonard and Nelson are more than historically great—they’ve set a new benchmark for what rookies can do. They’re the best rookie duo of all time.

Now, it’s worth pointing out that Pro-Football-Reference’s AV numbers for 2018 are currently provisional. Making the Pro Bowl is part of the AV calculation for offensive linemen and defenders, and the 2018 Pro Bowl rosters have not been finalized. But if the numbers do change at all, it could only boost the Leonard-Nelson duo. A Pro Bowl berth isn’t included in Leonard’s AV right now, but he could be named to the roster by the time the game is played on January 27.

But even before all that gets finalized, Leonard and Nelson will have a chance to add to their legend on Saturday, when the Colts travel to Arrowhead to take on the Chiefs. Indy is looking to pull off yet another upset win, and these two rookies will be crucial to achieving that. The Colts’ first priority in this game will be slowing down Patrick Mahomes II and the Chiefs offense—that will mean Leonard making plays on defense, and Nelson and the Colts’ running game draining the clock on offense. If the Colts can help keep the ball out of Mahomes’s hands, then they’ll have a shot—and a win would put Leonard and Nelson one step closer to accomplishing something none of the other duos on this list did as rookies: winning a Super Bowl.