From Latin America to Asia, from high school diamonds strewn with pebbles to college programs with world-class facilities, players climb upward through the ranks to reach the Major Leagues every year. They're baseball's most vital assets, sustaining the sport through generations of fans.
The most impactful newcomers vie for Jackie Robinson Rookie of the Year Awards, which will be handed out by the Baseball Writers' Association of America tonight at 6 ET on MLB Network. It's a tribute to the talent in the pipeline that even competition to be named one of the three finalists is intense.
Complete 2016 Awards coverage
Fifteen rookies were mentioned on the three-player Rookie of the Year Awards ballot last year, down from 21 in 2014. Those totals are likely to be high again this season, with the 2016 class unusually deep as teams get younger and more athletic.
Nobody epitomizes that trend more than Dodgers shortstop Corey Seager, who has a chance to follow Kris Bryant's example and receive all 30 first-place votes for the National League Rookie of the Year Award.

We know Seager's a heavy favorite for the rookie honor because he's also among three players named as a finalist for the BBWAA's NL Most Valuable Player Award. No NL player has won both awards in the same season, although it has happened twice in the American League (Fred Lynn in 1975 and Ichiro Suzuki in 2001).
While Seager's election has a chance to be anti-climatic, there's sure to be a split of opinions, and thus real drama, in the AL.

No AL rookie was as consistently productive as Yankees catcher Gary Sánchez, who hit .299 with 20 home runs and a 1.032 OPS, while throwing out 41 percent of runners attempting to steal. But Sanchez played only 53 games, not arriving to stay until early August.
Does that give him sufficient standing to overtake the front-runner, Tigers right-hander Michael Fulmer?

Fulmer, whom the Tigers acquired from the Mets for Yoenis Céspedes in 2015, made his debut on April 29 and stayed in Brad Ausmus' rotation all season. He finished 11-9 with a 3.06 ERA over 26 starts, throwing 159 innings. Fulmer would have ranked third in the AL in ERA had he thrown three more innings to qualify.
Should Fulmer be rewarded for five months worth of contributions over Sanchez's eye-popping impact in the last two months of the season?
There's precedent to go with Sanchez. The Giants' Willie McCovey was a unanimous pick in 1959 even though he played only 52 games. He was stuck at Triple-A behind Orlando Cepeda until July 30, but he wound up hitting .354 with 13 homers and a 1.085 OPS.
Center fielder Tyler Naquin, who helped the Indians reach the World Series, is the other AL finalist. He hit .296 with a .372 on-base percentage, 14 homers -- including a walk-off inside-the-park homer against the Blue Jays on Aug. 19 -- and an .886 OPS in 116 games.
The other two NL Rookie of the Year Award finalists are Dodgers right-hander Kenta Maeda, who was twice voted the top pitcher in Japan, and Nationals center fielder Trea Turner, who, like Sanchez, could have had a stronger case if he was promoted sooner.

Maeda, who had been a mainstay for the Hiroshima Carp, proved vital for the Dodgers with Clayton Kershaw missing all of July and August while recovering from a herniation in his lower back. Maeda helped the Dodgers win the NL West for the fourth consecutive year, going 16-11 with a 3.48 ERA while leading the staff with 32 starts and 175 2/3 innings.
Turner, a former North Carolina State star drafted by the Padres and traded to the Nationals, didn't arrive to stay in Washington until July 10. A natural shortstop, he was blocked in the middle infield by Daniel Murphy, an NL MVP Award finalist, and Danny Espinosa, who held off Turner by hitting 24 home runs and delivering a breakout season.
With Ben Revere slumping, the Nationals tried Turner in center and he revitalized the lineup. He instantly became one of baseball's best leadoff men, delivering a slash line of .342/.370/.567 while stealing 33 bases. Turner scored 53 runs in the 73 games he played.
"At the plate, he's aggressive,'' Dodgers manager Dave Roberts said. "You just see the confidence. And even seeing him when he first signed, when I had him in Spring Training [as a Padres coach], he was a confident young man. Obviously the skill set, the speed plays. He's a baseball player."

Seager, who had flashed his talent down the stretch and in the postseason in 2015, turned in a wire-to-wire season with about the same impact as Turner. His 6.1 WAR (baseball-reference) was by far the best of the rookies in either league. The Cubs' Bryant had a 5.9 WAR in 2015, when he was a unanimous NL Rookie of the Year Award pick.
The younger brother of Mariners third baseman Kyle Seager, Corey hit .308 with 26 home runs in 157 games, finishing with an .877 OPS. He played shortstop well enough (0 Defensive Runs Saved per FanGraphs, which ranked 13th among 24 qualfiiers) that there was little talk about how he would have to move to third base because of his size (6-foot-4, 215).
"I think they have one of the best players in the game in Seager at shortstop,'' Cubs manager Joe Maddon said during the NL Championship Series. "He is an incredibly good talent. Especially at the plate. He's different.''
Beyond the finalists, lots of rookies received consideration from the voters.
The list in the NL includes 31-year-old Brewers starter Junior Guerra, Cardinals shortstop Aledmys Díaz, Rockies shortstop Trevor Story (a likely finalist if he hadn't torn a ligament in his thumb in late July), Rockies starters Jon Gray and Tyler Anderson, Cardinals reliever Seunghwan Oh, Mets lefty Steven Matz, Pirates right-hander Jameson Taillon and Brewers right-hander Kyle Davies.
In the AL, the list includes Mariners closer Edwin Díaz (18-for-21 saves, 15.3 strikeouts per nine innings), White Sox shortstop Tim Anderson, Rangers outfielder Nomar Mazara, Twins outfielder Max Kepler, A's left-hander Sean Manaea, Astros right-hander Chris Devenski, Rangers right-hander Matt Bush, A's right-hander Ryan Dull, Astros third baseman Alex Bregman and Royals third baseman Cheslor Cuthbert.
Esurance MLB Awards week concludes Friday on MLB Network and MLB.com at 8 p.m. ET with the MLB Awards. Categories include Best Major Leaguer, Hitter, Pitcher, Rookie, Executive and Manager, and recognize overall MLB winners.