2020 Breakout Candidate: Will Carter Kieboom Rebound & Deliver On The Lofty Expectations?


The Nationals’ Carter Kieboom has long been a highly hyped prospect, and while there were continued strong results in the minors in 2019 when he got the call in the Majors he fell completely flat:

  • Triple-A – .303 (125-412), 16 HR, 79 RBI, 79 R, 5 SB
  • Majors – .128 (5-39), 2 HR, 2 RBI, 4 R, 0 SB

For many fantasy owners it will be easy to write him off, but do we really want to draw definitive conclusions off of 43 PA? Obviously it’s a minuscule sample size, which alone tells you downgrading him in any way would be a mistake. There are a number key facts that help to support ignoring the numbers from the Majors:

  • .143 BABIP – Kieboom simply didn’t have enough AB to get a good feel for the BABIP, but keep in mind that he wasn’t taking a fly ball-centric approach (39.1%), was using the entire field (26.1% Oppo%) and was hitting the ball hard (43.5% Hard%). Nothing in those numbers justify a poor mark, and keep in mind that he owned a .362 BABIP at Triple-A
  • 37.2% Strikeout Rate – While an 18.18% Whiff% against offspeed pitches wasn’t ideal, it also isn’t an atrocious mark that should lead to such a high strikeout rate. He was very good against all other pitch types and considering a 20.2% strikeout rate at Triple-A expecting an improvement is a given.

Are we really going to let such a small, skewed sample size wipe out all of the good he has done? Prior to 2019 he was considered one of the top prospects in the sport, including being our #5 Shortstop Prospect (click here to view the fill rankings), as we awarded him a B+ grade and said the following:

Kieboom split time between High-A (245 AB) and Double-A (248 AB), hitting .280 with 16 HR and 9 SB.  He showed an ability to draw a walk (10.4%) and a 19.5% strikeout rate is reasonable, though his overall 10.2% SwStr% is something worth monitoring.  Unsurprisingly all of the numbers took a step backward after his promotion:

  • Strikeout Rate – 21.6%
  • Walk Rate – 8.1%
  • SwStr% – 10.4%

The former first round pick didn’t turn 21 until September, so it’s easy to give him a little bit of a pass.  He may not have the elite talent of others, but having added 31 doubles and 1 triple it appears that he has the upside of being a 20/10 type player at the highest level.

While we can argue that there was a little bit of luck at Triple-A he actually showed an improvement in his SwStr% (9.0%) and an impressive ability to draw a walk (13.8% walk rate). He also continued to generate extra base hits (24 doubles, 3 triples and 16 HR over 494 PA) and the outlook we had entering 2019 shouldn’t change.

Kieboom remains a potential 20/10 player, and one who should be able to hit .280+ routinely. There’s a good chance that he enters 2020 with an opportunity to start (where depends on the offseason and the status of Anthony Rendon), and that should mean significant value for fantasy owners. He’s going to be a late round selection in many leagues, and he’s one that you are going to want to target regularly.

Sources – Fangraphs, Brooks Baseball

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