They come. They don't go.
Theo Epstein said he wanted to build a "player-development machine'' when the Cubs hired him as their president of baseball operations in 2011, and he's done exactly that. So many impactful position players have arrived in the past two years that you might feel you can't keep track of them.
So, we did. We also ranked them in the order of their potential career WAR (based on career WAR to date, adjusted per 150 games played). Then we looked ahead two more years and found seven more position players who could arrive at Wrigley Field within the next two years.
• Cubs' Top 30 Prospects
Consider this a young Cubs clip-and-save tool for the upcoming trading period, when Epstein is expected to seek upgrades that could pay dividends in October.
7 IN THE MAJORS
1. Kris Bryant
Age: 24
Debut: April 17, 2015
WAR/150: 6.0

In a nutshell: Bryant's smile pretty much tells the whole story. He's everything you'd want in a ballplayer -- a disciplined, powerful hitter in an athletic body with a graceful nature that caused him to be nicknamed "Silk'' when he was a teenager. He moved all over the field at the University of San Diego and has continued his wanderings in the Major Leagues. He's been a defensive asset at third base (+3 Defensive Runs Saved, per Fangraphs) and in left field (+5 DRS).
2. Willson Contreras
Age: 24
Debut: June 17, 2016
WAR/150: 5.6 (It was actually 11.25 before his home run on Wednesday. However, given the very small sample size we, cut it in half, figuring every week won't be like his first week).

In a nutshell: Contreras, a gift from former GM Jim Hendry to Epstein, has been in the Cubs' system longer than any player on the roster. The Venezuelan catcher is the complete package -- strong-armed behind the plate with the ability to hit for power and average (.338 with 17 home runs in 180 games between Double-A and Triple-A). He's a good bet to become the Cubs' primary catcher later this season, and MLB Network Radio's Jim Bowden says he could be the second best catcher in the NL in 2017, behind only Buster Posey.
3. Addison Russell
Age: 22
Debut: April 21, 2015
WAR/150: 3.4
Video: COL@CHC: Russell's nice play at shortstop
In a nutshell: The Cubs raised their level of play when he moved from second base to shortstop last August. He's a low-floor player whose quick hands and textbook mechanics -- "no chrome,'' according to Joe Maddon -- make him the kind of player who could win the Gold Glove Award every season once he wins his first one. Russell has a lot of room to grow as a hitter, with the improvement coming when he gets more comfortable against left-handers, surprisingly (.156 career average in 109 at-bats against southpaws).
4. Javier Baez
Age: 23
Debut: Aug. 5, 2014
WAR/150: 2.6 (Baez was such a raw product when he came to Chicago in 2014 that we calculated his WAR/150 using only 2015-16 totals; he'd be at 0.6 if you included his -1.0 WAR from '14).

In a nutshell: Baez, a natural shortstop who has been blocked by Starlin Castro and Russell, has developed into a very valuable depth piece. He makes spectacular plays at third base while using his quick hands to get outs on tag plays and his speed on the bases. Light-tower power was his calling card in the Minors, but he has cut down the length of his swing. Maddon has used Baez in 19 of the past 20 games, including 15 starts at third, short and second base. It may take a trade for him to have a position to call his own, but he wants to be remain a Cub. Like Contreras, Baez predates the Epstein regime in Chicago.
5. Albert Almora Jr.
Age: 22
Debut: June 7, 2016
WAR/150: 2.3 (like Contreras, he has played well within a small sample size, so we took his figure of 4.6 and cut it in half).

In a nutshell: As smooth as it gets in the outfield, Almora is a plus fielder. He was Epstein's initial first-round pick (2012) for the Cubs after being a regular on Team USA, and he appears very well-prepared after playing 379 games in the Minor Leagues. The question is whether the bat will be dynamic enough for him to inherit Dexter Fowler's job on a permanent basis. Fowler is only under the Cubs' control through 2016, but he is a strong candidate for a multiyear extension.
6. Kyle Schwarber
Age: 23
Debut: June 16, 2015
WAR/150: 2.3
Video: NLCS Gm1: Schwarber swats 459-foot home run
In a nutshell: It feels like Schwarber should be ranked much higher than this, but as a metric WAR generally rewards complete players (David Ortiz has averaged only 3.6 WAR in his 14 seasons with the Red Sox). He's as good of a hitter as Bryant -- the perfect left-handed complement -- and has homered once every 14.8 at-bats in the Major Leagues. Schwarber ruptured two ligaments in his left knee in a collision with Fowler in the second game of 2016. He's expected to make a complete recovery for '17. He'll get his spot back in left field and likely continue his work to be an option at catcher. He will make a deep, productive lineup deeper and more productive.
7. Jorge Soler
Age: 24
Debut: Aug 27, 2014
WAR/150: 0.8
Video: PHI@CHC: Soler belts one off Wrigley videoboard
In a nutshell: The jury's out on the muscular Cuban, who signed a nine-year, $30-million deal in 2012. He was the most consistent hitter in Maddon's lineup during the 2015 postseason (.474 with 3 homers, three doubles and six walks in 25 plate appearances), but he is batting .223 this season, and only .258 with a .745 OPS in 175 career games. Schwarber's injury opened left field for Soler this season, but he was in and out of the lineup before going on the disabled list with a strained hamstring. He's only touched on his potential, but he is getting squeezed among the outfield options. The Cubs could benefit from him hitting well when he comes off the DL, as he's a trade candidate.
7 WHO COULD BE CALLED UP IN THE NEXT 2 YEARS
1. SS Gleyber Torres
Age: 19
Current level: Advanced Class A
Video: Top Prospects: Gleyber Torres, SS, Cubs
How he fits: Part of an $8.2 million international spending spree in 2013, Torres potentially could allow the Cubs to deal Russell or Baez for pitching after 2017. He's an all-around player with a cannon arm and the ability to be a high-average hitter.
2. 3B Jeimer Candelario
Age: 22
Current level: Triple-A

How he fits: A switch-hitter who can be productive from both sides of the plate, Candelario can expect to be promoted in September, if not before then.
3. 1B/DH Dan Vogelbach
Age: 23
Current level: Triple-A
Video: Top Prospects: Dan Vogelbach, 1B, Cubs
How he fits: Vogelbach, a highly regarded hitter despite a soft frame, was the Cubs' second-round pick in 2011, behind Baez. He's an excellent candidate for a trade, especially to an American League team.
4. 2B/OF Ian Happ
Age: 21
Current level: Advanced Class A
Video: CHC@TEX: Happ drills a solo home run to right field
How he fits: An advanced hitter at the University of Cincinnati, Happ was a first-round pick in 2015 from the same folks who landed Schwarber in '14 and Bryant in '13. He's a switch-hitter with power and speed, profiling as a potential 20/20 player.
5. OF Mark Zagunis
Age: 23
Current level: Triple-A
Video: Top Prospects: Mark Zagunis, C/OF, Cubs
How he fits: A third-round pick in 2014 from Virginia Tech, the right-handed-hitting corner outfielder is an on-base machine ( .411 OBP in 236 Minor League games). With Jason Heyward set in right and Schwarber in left, Zagunis seems blocked, but he could challenge Soler and Matt Szczur for a role as complement to those two left-handed hitters.
6. OF Eloy Jimenez
Age: 19
Current level: Low Class A
Video: Top Prospects: Eloy Jimenez, OF, Cubs
How he fits: Jimenez has huge power and a right-field arm. It's probably a stretch to see him in a Cubs uniform before 2019, but he's an intelligent, hard-working player who could start moving quickly.
7. OF Billy McKinney
Age: 21
Current level: Double-A

How he fits: McKinney is left-handed hitter whose development has stalled after he fouled a ball off his right knee last August, sustaining a hairline fracture in his kneecap. He's the rare Cubs position-player prospect who is going the wrong way, but that could change quickly.
Also in the picture: OF John Andreoli, OF Jacob Hannemann, 3B Christian Villanueva, OF Eddy Martinez.