Most success with rookies
Los Angeles Dodgers, 38.6 total WAR: There's a steep drop-off from the Dodgers to the other clubs in this section, and their ability to turn quality young talent into instant Major League contributors is a big reason why Los Angeles won the NL West title in each of the years covered by this column. Corey Seager, between his 2015 and 2016 seasons, put up the highest WAR of any rookie over this span at 8.9, beating out even Judge and Kris Bryant (6.5). Yasiel Puig (4.1 in 2013) and 2017 NL Rookie of the Year Cody Bellinger (4.0) ranked eighth and ninth, respectively. Los Angeles also had Hyun-Jin Ryu (3.6 in 2013) and Kenta Maeda (3.3 in 2016) rank among the top 10 pitchers. The Dodgers have deep pockets -- helping them sign Puig and Maeda as international free agents -- but they've been unusually successful at getting contributions from rookies of all types.
St. Louis Cardinals, 30.4 total WAR: It's interesting to see the Cards here, given what's happened to their top-performing rookies in subsequent seasons. Randal Grichuk (3.7 in 2014 and 2015) and Aledmys Diaz (2.7 in 2016) rank first and third in WAR among St. Louis rookies over the last five seasons but were traded to the Blue Jays in separate deals this offseason. Former closer Seung Hwan Oh, who registered 19 saves and posted a 1.92 ERA, was the most valuable Cardinals rookie pitcher with his 2.6-WAR season in 2016, but he's now a free agent after failing a physical with the Rangers. Shelby Miller posted a 2.4 WAR season in 2014 -- and was third in Rookie of the Year voting -- but has long since been dealt to the Braves (and D-backs, in turn). The Cards still have a strong home-built base of recent vintage, however. Tommy Pham, Paul DeJong, Kolten Wong, Carlos Martinez, Jose Martinez, Michael Wacha and Alex Reyes have all been Cardinals rookies since 2013 and should play big roles for St. Louis in 2018.
New York Mets, 29.1 total WAR: Pitchers Jacob deGrom (3.5, 2014), Steven Matz (3.3, 2015/2016), Noah Syndergaard (3.1, 2015) and Robert Gsellman (2.1, 2016/2017) all hit the ground running for the Mets, particularly in their run to the 2015 World Series. But New York's 29.1 total WAR is evenly divided between hurlers and sluggers: 14.7 from pitchers, 14.4 from position players. Juan Lagares (2.9) was a defensive standout right away in 2013, and Michael Conforto (2.1) showed his bat was a Major League asset two seasons later in a rookie season that lasted only 56 games. The momentum built by Mets rookie hitters ran out of steam in 2017, however; Brandon Nimmo was the only position player worth more than one win (1.1 WAR) while Amed Rosario (0.3) and Dominic Smith (-0.6) both struggled out of the gate. That's not enough to write them off, of course, but it's not ideal for a club relying on homegrown talent while it goes through financial issues.
New York Yankees, 27.6 total WAR: Few players have been able to accomplish what Aaron Judge did as a Major League rookie. His 8.0 WAR ranks sixth-highest all-time among rookie position players. (Mike Trout is tops with 11.0.) Gary Sanchez impressed with his own power show, hitting 20 homers in 55 games and producing 3.1 WAR in 2016. The Yanks' spot here is also driven by a deep group of rookie arms. Dellin Betances, Masahiro Tanaka, Jordan Montgomery and Chad Green each posted rookie WARs of 2.4 or higher. It's no coincidence that all four, along with Judge and Sanchez, are expected to play big roles for the Yanks in 2018 and -- apart from Tanaka -- remain relatively inexpensive, allowing the historically big-spending club to acquire Giancarlo Stanton.
Biggest bang for buck
Cleveland Indians, 18.9 total WAR: The Tribe finished 10th in rookie WAR from 2013-2017 but ranked 27th in plate appearances by rookies and 28th in batters faced by rookies -- they got a great deal of value from the few youngsters they did play. Francisco Lindor is the headliner after posting 4.4 WAR over just 99 games in 2015, but Tyler Naquin (2.5, 2016), Roberto Perez (2.2, 2014/2015), Jose Ramirez (2.0, 2013/2014) and Bradley Zimmer (1.6, 2017) added plenty of heft. Lindor and Ramirez have become the cornerstones of Cleveland's run to two straight division titles and one pennant.
Washington Nationals, 16.4 total WAR: Same deal here, to a lesser degree. The Nats finished 25th in rookie plate appearances and 28th in batters faced by rookie pitchers, but their 16.4 collective WAR is right in the middle, ranking 15th among the 30 organizations. The bigger names are on the position player side, headlined by Trea Turner's 3.4-WAR effort in 2015 and 2016, but the pitchers produced the higher WAR at 9.1 total. The leaders there are the oft-injured Aaron Barrett (1.6, 2014/2015), who hasn't pitched since 2015, and Felipe Rivero (1.6, 2015/2016), who was traded to the Pirates. Recent rookies Anthony Rendon, Tanner Roark and Michael A. Taylor made less of an immediate impact but have become key contributors.
Lots of tries, little success
Cincinnati Reds, 6.8 total WAR: The Reds seem to have been in perpetual rebuild mode since last making the playoffs in 2013, and it shows in the ample playing time rookies have received over the last five seasons, especially on the mound. Cincinnati ranks first in batters faced by rookie pitchers since 2013 with 9,788. That's 1,062 more batters faced than the third-place Braves -- more on them in a bit -- and more than triple the 3,247 faced by the last-place Royals. What do the Redlegs have to show for all that young pitching? A tiny 0.2 collective WAR. Anthony DeSclafani is the big success story after posting 3.1 WAR and a 3.67 FIP over 184 2/3 innings in 2015, but his contributions were canceled out by those of David Holmberg (-1.7, 2014/15) and Amir Garrett (-1.2, 2017). Other rookies like Robert Stephenson, Cody Reed and Rookie Davis struggled out of the gate, and the rotation remains one of the biggest questions in Reds camp this spring. The good news is Luis Castillo looked like the real deal last year with a 3.12 ERA and 98 strikeouts over 89 1/3 innings as a rookie.
Atlanta Braves, 11.8 total WAR: The Braves rank 10th in total plate appearances by rookies and third in batters faced by rookie pitchers but sit just 21st in total WAR. That sounds bad, but is to be expected of a rebuilding club that's relied on youth rather than Major League talent while it waits for its talented prospects to arrive. To be sure, Dansby Swanson's rookie campaigns didn't go as well as anyone hoped -- he posted a 0.9 WAR over 182 games in 2016 and 2017 -- and there have been a handful of rookie success stories like Ozzie Albies (1.9, 2017) and Julio Teheran (2.5, 2013). But this is also an organization that gave Tyrell Jenkins 52 innings worth -1.0 WAR in 2016, Matt Wisler 109 innings of 0.1-WAR ball in 2015 and Tommy La Stella 360 plate appearances worth -0.2 WAR in 2014. If those players had stuck, Atlanta would have been happy. But until the likes of Ronald Acuna, Kyle Wright, Mike Soroka and others arrive in the Majors, the Braves were content to take a "sink or swim" approach with youngsters rather than spend on bigger names.
Little reliance on rookies
Kansas City Royals, 11.7 total WAR: If we expanded the sample to include 2012, this would be a different story. By 2013, the Royals had completed their rebuild and posted their first winning season since 2003. The following year they would reach Game 7 of the World Series and of course captured their first title since 1985 in 2015. As such, Kansas City didn't have much time for rookies, ranking 28th in rookie plate appearances and dead last in batters faced by rookie pitchers. Yordano Ventura (2.4 WAR, 2013/2014) was the most notable Royals youngster over this span and the only hurler to toss more than 100 innings as a rookie. Cheslor Cuthbert and Jorge Bonifacio were the only hitters to receive 400 plate appearances as rookies. These trends may now change depending on how Kansas City moves forward without Eric Hosmer and potentially Mike Moustakas.
Toronto Blue Jays, 10.9 total WAR: With 1,837, the Jays were the only club to give rookies fewer than 2,000 plate appearances from 2013 to 2017. By comparison, the White Sox led the way with 6,316 rookie plate appearances. Ryan Goins was the only Jays position player to receive more than 300 plate appearances, notching -0.1 WAR in 2013 and 2014. Among pitchers, Marcus Stroman's killer 2014 rookie campaign, during which he posted a 3.65 ERA and was worth 3.0 WAR over 130 2/3 innings, gets included here, but he and Aaron Sanchez (0.8 WAR, 2014/2015) were the only rookie hurlers to pitch more than 100 innings. Like the Royals, this trend could change quickly with Vladimir Guerrero Jr., Bo Bichette and Anthony Alford all closing in on the Majors.
Chicago Cubs, 17.3 position player WAR, 5.2 pitching WAR: Naming prominent recent Cubs rookie hitters is fairly easy task with the likes of Kris Bryant (6.5 WAR, 2015), Addison Russell (2.9, 2015) Albert Almora Jr. (2.0, 2016/2017), Willson Contreras (2.2, 2016), Ian Happ (1.8, 2017) and Kyle Schwarber (1.8, 2015) all arriving in the last five seasons. Notable rookie pitchers are harder to compile. Carl Edwards Jr. (1.6, 2015/2016/2017) and Kyle Hendricks (1.5, 2014) come to mind, but it's a long drop-off from them to Tsuyoshi Wada and Chris Rusin, who ranked third and fourth in innings pitched for Cubs rookies with 69 1/3 and 66 1/3 respectively. That's why the North Siders signed Jon Lester and Yu Darvish and traded for Jose Quintana; they just haven't produced enough quality arms in their system to fill a contending rotation.
Boston Red Sox, 12.4 position player WAR, 2.2 pitching WAR: Similar deal here. Eduardo Rodriguez (1.7 WAR, 2015) is the only Red Sox rookie hurler to be worth more than one win over the last five seasons. By contrast, seven rookie position players met that requirement, led by Andrew Benintendi with 2.8 WAR over the 2016 and 2017 campaigns. That's not for lack of trying. Henry Owens, Brian Johnson, Anthony Ranaudo, Allen Webster and Matt Barnes were all Top-100 prospects at some point, but none will begin 2018 in Boston's rotation. No wonder the Sox were willing to pay the high price in prospects to get Chris Sale last offseason and in money to land David Price the season before that.
Milwaukee Brewers, 5.6 position player WAR, 19.2 pitching WAR: Time to flip the script. The Brewers lead all 30 clubs in collective WAR by rookie pitchers since 2013. That's not because of a couple dominant arms, though Zach Davies' 3.2 WAR over 2015 and 2016 stands out. Rather, the Crew has done a good job of bringing up arms when they've ready -- only nine of their 37 rookie pitchers since 2013 performed below replacement level. By comparison, 24 of their 65 rookie position players failed to reach 0.0 WAR. There could be more rookie pitchers on the way as Brandon Woodruff and Corbin Burnes rise through the system. It shouldn't be a surprise that Milwaukee's biggest splashes this offseason involved the acquisition of position players Christian Yelich and Lorenzo Cain.
Colorado Rockies, 3.8 position player WAR, 15.6 pitching WAR: Rockies pitchers succeeding? That's the way it's gone recently as Colorado adjusted its approach. Enticing free-agent pitchers to the Mile High City is difficult, so to be good, the Rockies have to rely on homegrown arms. They've done a solid job lately, and coming off their run to the second NL Wild Card spot last season, all five projected members of the Rockies rotation spent time as Colorado rookies in the last five seasons. Jon Gray hit the ground running for 4.4 WAR between 2015 and 2016, but German Marquez (2.6 WAR, 2016/2017), Tyler Anderson (2.5, 2016) and Kyle Freeland (2.0, 2017) also found success in the last two seasons. Among position players, Colorado can claim Trevor Story (2.9, 2016) and Nolan Arenado (2.4, 2013) as rookie success stories.