The road to a Most Valuable Player Award can be traveled by a can't-miss young phenom speeding to his lofty potential like Bryce Harper, or by a player whose promise gradually blossomed into stardom after a detour or two like Josh Donaldson. As long as you put up a season that beats them all, baseball's greatest individual reward is yours for the taking.

The two players judged by the Baseball Writers' Association of America to have been the very best in their respective leagues in 2015 were crowned Thursday night, with Harper of the Washington Nationals claiming National League MVP honors in a unanimous vote and Donaldson of the Toronto Blue Jays capping off his remarkable season with the American League MVP in a strong showing ahead of three-time runner-up Mike Trout.

Complete 2015 Awards coverage

By winning the award in his age-22 season, Harper becomes the fourth-youngest MVP in history, the youngest unanimous winner ever and the youngest to earn the honor since Vida Blue became the youngest in history in 1971. The first in Nationals/Montreal Expos franchise history to win MVP, Harper took all 30 first-place votes based on two ballots from each league city submitted prior to postseason play.

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Already a star even before the Nationals drafted him at age 17 in 2010, Harper excelled in every aspect of the game in his fourth full season in the big leagues to reach MVP status. Harper was determined this was going to be the year it all came together.

NL MVP voting

"At the beginning of the year," Harper said upon winning the award, "that was my goal, from Day 1. Absolutely, to win a World Series and get to the playoffs, but No. 2 to be able to win an MVP and do the things I could to help my team win every single day."

After doing so with unparalleled power and patience, Harper was one of four MVP finalists this year whose magnificent years did not include a trip to the postseason. On the other side of that coin, Donaldson's leading role in pushing the Blue Jays to the playoffs was key to his AL accolade.

Donaldson, who as recently as 2011 was primarily a catcher at Triple-A, crushed baseballs at the plate and made the spectacular look routine at his true calling of third base for the Blue Jays, providing the catalyst for Toronto's first trip to the postseason since 1993. Traded by the A's to the Blue Jays last November, Donaldson gained 23 of the possible 30 first-place votes and seven second-place nods, with Trout taking the other seven first-place votes and finishing well behind Donaldson in total voting points, 385-304.

Donaldson became the heart and soul of a Blue Jays lineup that scored 891 runs, or 127 more than the No. 2 team in all of MLB, and he knows being a key cog in a very deep and dangerous Toronto lineup helped earn him this award.

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"I was very blessed to be in the situation I was put in," Donaldson said. "I'm very thankful, and I felt like I was able to take advantage of a lot of the opportunities that I had put in front of me."

Video: Duquette compares MVP winners Donaldson, Harper

Donaldson stood out on an AL ballot that had a large separation from the pack by the two top finishers, with the Royals' Lorenzo Cain finishing a solid third over fourth-place finisher Manny Machado, the Orioles' third baseman. AL Cy Young winner Dallas Keuchel of the Astros finished fifth, one of four pitchers to receive votes on the AL ballot.

AL MVP VOTING

For Trout, a third runner-up in four years ties him with three-time MVP Mickey Mantle, one behind the record of four second-place finishes, shared by Stan Musial, Ted Williams and Albert Pujols.

The NL ballot left little room for suspense, as Harper rolled a perfect game to become the first unanimous pick in the NL since Pujols in 2009 and the seventh overall. Paul Goldschmidt of the D-backs was runner-up for the second time in three years, earning 18 second-place votes to finish ahead of the Reds' Joey Votto. Cubs pitcher Jake Arrieta finished sixth with five second-place nods, the second most after Goldschmidt, and was one of five pitchers receiving votes on the NL ballot.

Harper led the Majors with a 1.109 OPS while totaling 42 homers, 124 walks and 118 runs scored, becoming the youngest player in history to hit those three marks in a season. He supplemented his historic campaign at the plate with upgraded defense in right field and an overall maturation into one of the game's great overall talents, as advertised.

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"I enjoy playing baseball out there," said Harper, the 16th former Rookie of the Year to go on to win MVP. "I enjoy putting MLB on the map and doing everything I can to further this game for young talent across the world. This game is just getting better and better with the talent and everything that's happening in the game right now. It's very exciting for the fans, very exciting for everybody that plays."

At 22 years, 353 days old on the final day of the season, Harper was the third-youngest player to win NL MVP, behind Hall of Famers Johnny Bench (22 years, 298 days for the Reds in 1970) and Musial (22 years, 316 days for the Cardinals in '43). Blue is the youngest MVP in baseball history, having won the AL MVP Award for the A's in 1971 at 22 years, 64 days old. This is just the 12th time in MLB history that a league's MVP has been younger than its Rookie of the Year Award winner; Cubs phenom Kris Bryant won that honor this year and was 23 years, 272 days old at the end of the regular season.

Video: NL Most Valuable Player: Bryce Harper

Donaldson, who will turn 30 on Dec. 8, had a much different road to the MVP than Harper, going through a trade from the Cubs and a position change to third base before he really got his Major League career started with the A's in 2012, at age 26. Fast forward to 2015, and he became the eighth third baseman to win AL MVP in his first season with Toronto following a blockbuster trade with Oakland, fitting right in with his new team and becoming the second Blue Jays MVP after George Bell in 1987.

"It's been a journey, that's for sure," Donaldson said.

As the No. 2 hitter in the Blue Jays' lineup, batting ahead of sluggers Jose Bautista and Edwin Encarnacion, Donaldson had his opportunities to shine, to be sure, but he took advantage of more than enough of them to prove he was the AL's top overall performer. Also voted the Player of the Year for all of MLB by his peers in the Players Choice Awards, Donaldson put up a run of career numbers, batting .297 with 41 homers, 123 RBIs and a .939 OPS.

Video: Donaldson wins the 2015 BBWAA AL MVP award

After being a huge part of postseason runs by the A's the previous three years, Donaldson rode the wave of success the Blue Jays were on during the second half of the season, carving his own niche in a remarkable season in Toronto, leading by example with hard work and unrivaled competitiveness.

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"Honestly, our team was on a roll, so I was able to deflect from myself and think I was just going out there trying to help my team win," Donaldson said. "That's how you end up winning awards, not by focusing on individual stats. You go out there and you play to win the game."