Albies and Acuna: Baseball's newest source of alliterative elegance is enough to inspire rapture (from Atlantans), revulsion (from opponents) and research (from me). Because let there be no mistaking that what the 21-year-old Ozzie Albies and 20-year-old Ronald Acuna Jr. are doing at the top of the Atlanta order is rare.
Oh, sure, there have been some astounding seasons from players who have not yet hit the age (22) once celebrated by Taylor Swift. But when you take Albies and Acuna in tandem, there aren't very many statistical comparables to these Baby Braves.
Albies, who has probably already banged out another couple extra-base hits just in the time you've been reading this, has already been worth 1.7 Wins Above Replacement (per Baseball Reference), as of this writing. Acuna was on pace to be worth at least 1.0 WAR.
Even if we just set the bar there -- just one win above replacement-level (and Acuna has shown plenty of potential to cruise past that mark) -- how unusual is it for a club to possess two everyday players south of 22 who make that level of contribution in a single season?
Well, does 15 times in 117 completed seasons strike you as unusual?
To be clear, we're focusing this discussion, which is possible thanks to the help of Baseball Reference's Play Index, solely on position-player combos, as that is most comparable to what we're seeing down in Atlanta right now. But a quick shoutout to Mark Prior-Carlos Zambrano (2002 Cubs), Mark Gubicza-Bret Saberhagen (1984 Royals), Don Drysdale-Sandy Koufax ('57 Brooklyn Dodgers) and all the other precocious pitching pairs that have graced our game over the years.
On to the list of position-player pups. And just for fun, let's rank 'em.
15. Braggo Roth (21) and Ray Schalk (21), 1914 White Sox
Schalk, a catcher, finished sixth in the Chalmers Award (read: Most Valuable Player) voting, but, as you might suspect, the guy nicknamed Braggo (because of his boastful nature) is more interesting here. The South Siders purchased his contract from the Kansas City Blues of the American Association in August, and he played well. When his outfield defense slipped the next season, the White Sox dealt him to Cleveland as part of the trade for none other than "Shoeless" Joe Jackson and, well, you know where that led.
14. Gus Bell (21) and Danny O'Connell (21), 1950 Pirates
These two rookies were, fortunately, more distinguished than the team logo at the time. O'Connell was added midseason and wound up finishing third in the Rookie of the Year vote before missing the 1951-52 season while serving in the Korean War. Bell went on to become a four-time All-Star with the Reds.
13. Bob Coluccio (21) and Darrell Porter (21), 1973 Brewers
Though Porter, who finished third in the Rookie of the Year voting in '73, had a long career that featured four All-Star appearances and a World Series MVP turn in 1982, his legacy unfortunately includes the battles with substance abuse that ultimately led to his tragic death at age 50. Coluccio's big league success was short-lived. He logged just 246 more games through 1978 after hitting 15 homers, 21 doubles and eight triples in this rookie effort.
12. Dave Cash (21) and Richie Hebner (21), 1969 Pirates
Hebner was handed the third-base job as a rookie after Maury Wills was taken by the Expos in the expansion draft. He responded with a .301 average and .801 OPS and would go on to play in the bigs into the 1985 season. Cash, a second baseman, was a late-season callup who showed the flashes of the solid singles hitter and reliable defender he'd become.
11. Milt May (20) and Rennie Stennett (20), 1971 Pirates
Just a couple kids helping out a World Series winner. No biggie.
May made the most of his limited role as a backup catcher and pinch-hitter (.750 OPS in 49 games) and then had a pinch-hit RBI single to drive in the winning run in Game 4 of the Fall Classic. (May went on to briefly replace Roberto Clemente in the outfield after Clemente's death prior to the 1973 season.) Stennett had an .834 OPS in 50 games and was the leadoff hitter for the Majors' first all-black and Latino lineup on Sept. 1 of that year.
10. Rocco Baldelli (21) and Carl Crawford (21), 2003 Devil Rays
We'll always be left to wonder what kind of career Baldelli could have had if a cell condition that caused muscle fatigue hadn't begun hampering him in 2005. But in '03, he and Crawford made for an electric rookie pairing in the then-still-bedeviled Rays' outfield. They combined for 169 runs scored, with Crawford stealing 55 bags and Baldelli 27 while providing terrific defense, as well.

9. Tommy Davis (21) and Willie Davis (20), 1960 Dodgers
Willie Davis was a late-season callup who needed just 22 games to compile his 1.0 WAR, and he officially supplanted Duke Snider in center field the following season. Tommy Davis (no relation) was in the rookie year of a long career that would see him win consecutive batting titles in 1962 and '63.
8. Luis Castillo (20) and Edgar Renteria (19), 1996 Marlins
Installed as the Marlins' starting shortstop in May, Renteria was the runner-up to the Dodgers' Todd Hollandsworth in the National League Rookie of the Year voting, with a .309 batting average and .358 OBP. The following year, he came through with the World Series-winning hit -- and not for the last time. Castillo spent most of the year in Double-A and didn't join the big club until August. But in just 41 games, he made a major defensive impact at second base and stole 17 bags.

7. Freddie Freeman (21) and Jason Heyward (21), 2011 Braves
Yes, the Braves have been here before.
Actually, the '11 season marked a pretty severe statistical regression for Heyward from his NL Rookie of the Year runner-up performance a year earlier. His OPS dipped from .849 to .708, but his defense helped his overall WAR score (ask the Cubs about that). Freeman, with a .282/.346/.448 slash, was the rookie runner-up this time around. Teammate Craig Kimbrel edged him for that honor. But at 23, Kimbrel was an old man, by comparison.

6. Eric Hosmer (21) and Salvador Perez (21), 2011 Royals
Clearly, 2011 was a good year to be 21 (although in truth, is there really a bad year to be 21?). The 2011 Royals, meanwhile, weren't very good, but the seeds of their eventual back-to-back American League titles and '15 World Series championship were sewn right here (Mike Moustakas and Greg Holland were also rookies on the 2011 team). Hosmer closed with a sizzling September (.349/.360/.557 slash), and Perez joined the club in August and churned out a .331/.361/.473 with excellent defense behind the dish.

5. Gary Carter (21) and Larry Parrish (21), 1975 Expos
The Giants' John "The Count" Montefusco was the NL Rookie of the Year in '75, but Carter (.270 average, 17 homers, 68 RBIs) finished second and Parrish (.274, 10, 65) finished in a tie for third. Carter was named to the first of his 11 All-Star teams. But while the Hall of Famer will be remembered as one of the greatest catchers of all-time, he actually logged more innings in right field in '75.
4. Joe Morgan (21) and Rusty Staub (21), 1965 Astros
Though they were both just 21, Staub had the better part of two big league seasons under his belt by the time the 1965 season -- Houston's first after the transition to the name Astros from Colt .45s -- dawned. Staub took a major step forward as a hitter, with a .256/.339/.412 slash while serving as the primary right fielder. But the future Hall of Famer Morgan was the real revelation, drawing a Major League-high 97 walks while hitting a respectable .271. He finished second to Jim Lefebvre in the NL Rookie of the Year vote.
3. Alan Trammell (20) and Lou Whitaker (21), 1978 Tigers
Trammell is finally headed to Cooperstown this summer. And if there's any justice, Whitaker, his longtime double-play partner, will join him in 2020 (after the next modern era committee ballot). Though they both came up late in the '77 season, this was their first full year of making magic in the middle of the diamond together. The Tigers, not coincidentally, had their first winning season in five years.

2. Bobby Doerr (21) and Ted Williams (20), 1939 Red Sox
This was Teddy Ballgame's rookie year, and his .327 average, 31 homers, 44 doubles and 11 triples were a reasonable sign of things to come. Doerr was in his second season as a Red Sox regular and, with a .318 average and .813 OPS, was just beginning to flash the bat that would eventually make him a nine-time All-Star. They had polar-opposite personalities -- Williams bombastic, Doerr genteel -- but these two teammates helped restore the Red Sox, turning them into a serious threat to the Yankees' supremacy in the AL.
1. Orlando Cepeda (21) and Willie McCovey (21), 1959 Giants
Albies and Acuna can only hope to be on the same overall career track as these two Hall of Famers. But there was awkwardness to the Cepeda-McCovey arrangement because they both played first base.
McCovey followed in Cepeda's '58 footsteps with a unanimous win in the NL Rookie of the Year voting, needing just 52 games to sway the voters with his .354 average, 13 homers, nine doubles and five triples in 192 at-bats. When McCovey arrived, Cepeda shifted to third base to accommodate McCovey at first. That lasted all of a few games before Cepeda was moved to the outfield, and a few years later, the Giants moved McCovey to the outfield to appease an unhappy Cepeda.
It finally ended with the Giants making a regrettable trade of Cepeda to the Cardinals for Ray Sadecki in 1966 -- a deal that may have cost them the pennant. (You paying attention, Atlanta? Don't trade Albies or Acuna!)