The only way you'd ever guess they were first-year big leaguers is by looking at the back of their baseball cards.
With the 2014 season now in the rearview mirror, it's time to break out the annual end-of-year honors from the Baseball Writers' Association of America, and today will bring us the first pair: the Jackie Robinson Rookie of the Year Awards.
The winners, which will be announced today at 6 p.m. ET on MLB Network with additional coverage on MLB.com, will be the leading BBWAA vote-getters from a terrific trio of finalists in each league, players who demonstrated so much talent and professionalism beyond their Major League service time that they seemed like veterans.
The National League's Rookie of the Year will be won by either New York Mets starting pitcher Jacob deGrom, Cincinnati Reds outfielder Billy Hamilton or St. Louis Cardinals second baseman Kolten Wong.
In the American League, the award will go to either first baseman/designated hitter Jose Abreu of the Chicago White Sox, reliever Dellin Betances of the New York Yankees or starting pitcher Matt Shoemaker of the Los Angeles Angels of Anaheim.
The case for ...
• Jacob deGrom, Mets
• Billy Hamilton, Reds
• Kolten Wong, Cardinals
• Jose Abreu, White Sox
• Dellin Betances, Yankees
• Matt Shoemaker, Angels
The NL winner for 2013, Miami Marlins pitcher Jose Fernandez, hadn't yet hit his 21st birthday when he began his stellar inaugural campaign on April 7. Last year's AL winner, Tampa Bay Rays outfielder Wil Myers, earned his hardware on the basis of a strong offensive season, even though he didn't break into the big leagues until mid-June.
This year's finalists have varied skill sets and showed eye-popping production and versatility in their lid-lifting seasons.
Take deGrom, who is the favorite for the NL honor based on the fact that last week he won the Players Choice Award for NL Outstanding Rookie. The right-hander was hardly on the Mets' big league radar prior to the season, ranked as the 19th-best prospect in the team's farm system and coming off a 2013 in which he compiled a 4.51 ERA and a 7.3 strikeouts per nine innings across stints in Class A, Double-A and Triple-A.
Video: NL Rookie of the Year Finalist: Jacob deGrom
So naturally, all he did at the age of 26 was seize a spot in the Mets' starting rotation in mid-May and go 9-6 with a 2.69 ERA in 22 starts, striking out 144 in 140 1/3 innings (9.2 strikeouts per nine innings) and only walking 43 batters. He went 3-0 with a 1.32 ERA in his last five starts, striking out 11 per nine innings in that stretch. During one September outing, he struck out the first eight batters he faced. Now he looks like a lock for what could be an outstanding 2015 rotation that's expected to get back Matt Harvey.
Video: deGrom on winning 2014 NL Outstanding Rookie award
"We're just extremely proud with the way Jake's gone about his job," Mets manager Terry Collins said. "Certainly, no matter what happens when those ballots are cast, he's had an outstanding year for a guy who was off the radar.
"What he's done, it is truly remarkable. I understand what a year Billy's had and what a year Kolten Wong has had. But I don't know if they're as good as my guy's been this year."
Hamilton came into the 2014 season with a reputation as a supreme basestealer who would get a chance to show that he could get on base at the Major League level. He ended up showing a different and more enticing set of tools that bode well for his future with the Reds.
Hamilton, 24, seized the leadoff spot for Cincinnati and hit .250 with six home runs and 48 RBIs while stealing 56 bases to rank second in the NL in that category behind the Dodgers' Dee Gordon. Hamilton's total broke a 105-year-old single-season club record for a rookie.
Hamilton also led all NL rookies in runs, hits, steals, RBIs, doubles, extra-base hits and total bases while playing in 152 games, and he sparkled defensively in center field, even though he came up through the Minors as a shortstop. An NL Gold Glove Award finalist, Hamilton led all NL center fielders with 10 assists and a .994 fielding percentage while posting a 20.1 ultimate zone rating (UZR) and 14 defensive runs saved.
Video: NL Rookie of the Year Finalist: Billy Hamilton
"I'm very pleased with how he's handled it physically," Reds manager Bryan Price said. "I'm even more impressed with how he's handled it mentally. Of course, everyone's curious about this kid. He's got a lot of things coming at him for the first time at this pace and intensity. From at least what I've witnessed, he's handled it very well."
The Cardinals and the rest of the baseball world could say the same about Wong after watching him rack up seven extra-base hits in October, including a walk-off home run in the NL Championship Series, but he was solid in the regular season, too.
The 24-year-old, who had played in the 2013 World Series after a late-season callup, qualified as a rookie for 2014 and did just fine, ranking in the top seven among rookies in slugging percentage (.388), hits (100), doubles (14), homers (12) and RBIs (42).
Video: NL Rookie of the Year Finalist: Kolten Wong
In the AL, Abreu comes into this award season as the overwhelming favorite. The 27-year-old, who signed as a free agent from Cuba last fall, has already been selected as the top AL rookie by the Players Choice Awards and the Sporting News, and it's easy to see why.
Video: Paul Hagen dishes on AL Rookie of the Year candidates
Abreu put up MVP-caliber numbers, batting .317 with 36 home runs, 107 RBIs, 35 doubles, a .581 slugging percentage that led the Major Leagues and a .383 on-base percentage.
Abreu is the first rookie in baseball history to rank among the top five in his league in each Triple Crown category.
Video: AL Rookie of the Year Finalist: Jose Abreu
"When you think of an MVP, you're just looking at his body of work," White Sox manager Robin Ventura said. "I know there are other factors that go into it, but he deserves to be up there just by the year he's had and what he's meant to our team as well. Throughout the league, he's done some things that nobody else has done."
So has Betances, whose conversion from starting prospect to star big league reliever has him in the final three for AL Rookie honors.
Betances, the 6-foot-8 26-year-old from Brooklyn, seized the Yankees' setup role and finished up the year with a firm grasp on the eighth inning (or possibly the ninth) for 2015 with spectacular numbers. He struck out 135 batters in 90 innings to break Mariano Rivera's 1996 franchise record for strikeouts by a reliever. He ended up 5-0 with a 1.40 ERA in 70 appearances, led all AL relievers in innings pitched and held opponents to a .149 batting average. His WHIP was 0.78.
Video: AL Rookie of the Year Finalist: Dellin Betances
"He's been awesome for us all year," Derek Jeter said late in the season. "It seemed like Mo pitched two innings every time toward the middle and end of '96; Dellin's been doing the same thing. He's pitched a lot of innings. Any time he gets guys on base, he's capable of getting out of trouble because he can strike guys out."
The last AL candidate, Shoemaker, was another unexpected revelation for his team. The 28-year-old right-hander, an undrafted free agent signed by the Angels in 2008, began 2014 in the club's bullpen, joined the starting rotation in May and ended up 16-4 with a 3.04 ERA for a team that had been decimated by injuries to pitchers.
By the time the playoffs rolled around, Shoemaker was indispensable, and he figures to be thought of in that manner for 2015.
Video: AL Rookie of the Year Finalist: Matt Shoemaker
"You can't really put words to it," Shoemaker said during the AL Division Series against Kansas City. "In Spring Training, I was just trying to make the club in whatever position they needed me, and it slowly developed into the starting role. It's been a great ride."
Shoemaker could be speaking about the 2014 seasons that all six Rookie of the Year Award finalists enjoyed. On Monday, we'll get to see who makes the history books.
Doug Miller is a reporter for MLB.com. Follow him on Twitter @DougMillerMLB.