For some reason saying "PECOTA comparable" reminds me of "potent potables.' So that describes the header image. What comes next has nothing to do with Jeopardy, SNL, or Alex Trebek, but does have something to do with the PECOTA comparables and Similarity Index.
While the PECOTA Similarity Index isn't an exact science or something that should be taken as a sole projection, it does use historical player comparisons to give the reader a glance at what other players have had similar results as another player.
The Similarity Index as described by Baseball Prospectus, the owner of the PECOTA system, says
Similarity Index is a composite of the similarity scores of all of a player's comparables. Similarity index is a gauge of the player's historical uniqueness; a player with a score of 50 or higher has a very common typology, while a player with a score of 20 or lower is historically unusual. For players with a very low similarity index, PECOTA expands its tolerance for dissimilar comparables until a meaningful sample size is established.
Comparable Players are generated by taking a player's baseline projection and finding players with the same age and similar contact, power on contact, walks, and strikeout rates, as well s similar height, weight, handedness, and position (or start/relief split for pitchers).
It's also important to note that established major leaguers are compared to other major leaguers only, while minor-league players may be compared to major-league or minor-league players, with PECOTA strongly preferring the latter. All comparables represent a snapshot of how the listed player was performing at the same age as the current player, so if a 23- year-old hitter is compared to Miguel Tejada, he's actually being compared to a 23-year-old Tejada, not the decrepit Giants version of Tejada, nor to Tejada's career as a whole.
While the description above specifically says that the SI is only a comparison of the player at his specific age and not a comparison, or if you further extract that idea then a projection, of the players current age or career, there still seems to be some semblance of validity, if only for fun, to using it as a career path.
So let's take a somewhat subjective look, but mainly objective, at some of the Royals better prospects and their age comparables.
*Note* These were created PRIOR to this season start. Any 2014 stats haven't been included in the comparable list.
Similarity Index 86
Gilmartin was a former first round, 28th overall, pick by the Braves out of Florida State. He was once the Braves #6 prospect. Gilmartin never quite had the upside of Zimmer, more of a mid-rotation ceiling, and his fastball generally sat in the low-90's to high-80's. Gilmartin was recently just traded to the Twins for Ryan Doumit.
Most of us know the ballad of Tommy Hanson. Once a top prospect, BA #4 in 2009, he debuted at age 22 and put up a four win season his sophomore campaign. Then a shoulder injury(ies) came along and he was never the same since.
Will Inman was once a Top-100 prospect, but is now 26, never pitched a major league inning, and is a reliever for the Rays AAA team.
Finally a positive one; Johnny Cueto. I'm not alone likely in saying that this would be a nice career outcome for Zimmer. Cueto is Top-10 in the majors in fWAR and is two years removed from a 4.5 win season. Much like Zimmer, if Cueto is healthy he's generally pretty good.
Friedrich was once a Top-25 prospect for the Rockies and a first round pick. After being filthy for several years in the low minors, Friedrich hit a wall in AA, debuted in 2012, made 16 starts with a 6.17 ERA and hasn't pitched in the bigs since.
Similarity Index 86
Really not even going to break this one down. You can imagine the volatility of looking at young Latin American players in the low minors.
Should be noted that Mondesi is younger than all these players and was generally younger at each stage up to A+.
Similarity Index 87
Lot of noise in this one.
Deck McGuire was a #11 overall pick for the Blue Jays, but now at age 25 is yet to make his major league debut.
Carrasco was a multi year Top-50 prospect for the Indians, but injuries and never having a solid spot in the Cleveland rotation has made him an enigma of sorts. He has a similar repertoire as Ventura with a 70 grade fastball and big curve, but Carrasco is much taller and heavier.
Chafin was a first rounder for the Diamondbacks. He's done a good job getting batters out in other means than the strikeout, but has spotty control. Chafin has undergone Tommy John previously as well.
Gio Gonzalez sounds like a good career for Ventura. Gonzalez has been through three organizations already (White Sox, Oakland, and Washington), but has been very good in every year he's pitched including a five win season. He's made multiple All-Star appearances, finished third in Cy Young voting, and received MVP votes.
Jeremy Hellickson is a former Rookie of the Year winner, but it seems like his peripherals have finally caught up to his ERA. Underwent elbow surgery (not TJS) this season.
Similarity Index 86
Really no one of note on this list other than Jedd Gyroko.
Campbell is bench player for the Mets who at age 27 is hitting .282/.348/.436 in 18 games.
Matt Skole is an interesting similarity. Like Dozier, Skole had a high average and high OBP age 22 appearance in the Carolina League, albeit it for only 18 games. Skole played two games in AA, but then succumbed to Tommy John Surgery and voided that season. Upon to returning to AA this season, now 24, he's hitting .221/.307/.347 and doesn't seem to be the same high -walk high-average guy he once was.
Wheeler is a career minor league player.
Gyroko was a solid prospect for the Padres. He was a guy who did a lot of things good; hit for average, some power, got on base via the walk, and played okay defense at 3B. Gyorko debuted last year and put up a 2.5 win season thanks to a rookie leading 23 home runs (at Petco none the less) and a 110 wRC+. Gyrko has come down since last year a bit and has struggled with a foot injury this season.
Similarity Index 82
Finally some fun names to play with.
Admittedly, Jackson used to be one of my favorite prospects. A former first rounder, Jackson went from a back end Top-100 prospect to a to a mid Top-100 guy. He had big time power, good speed, drew walks, and played centerfield defense well. He fell five home runs short of a 20-20 season in AAA at age 23. Jackson biggest problem though was that when he wasn't walking or hitting home runs...he was striking out...and a lot. The Cubs called him up at age 23 and put up a 175/.303/.342 line in 44 games with four home runs but a 41.5% strikeout rate and they mercifully sent him back to the PCL. An inury took a bite of his 2013 season and now 25 and in AAA, Jackson is completely lost.
Austin Jackson is a name we all know out of Detroit. Jackson had a monster age 25 season that saw him put up 5.2 wins on the back of some stolen bases, some home runs, a good average and OBP, and solid CF defense. Jackson had contact issues when he was a prospect and was the owner of some high-ish K%, but has come around as a very good centerfield piece.This would be a wonderful Starling career arch...
Everyone else on this list shares common themes: speed/power outfielders with good defense but poor bat to ball skills and plate discipline. The risk/reward on these guys are extreme as in the case of Austin Jackson but then there's Jordan Schafer; once the #17 overall prospect, but now in a bench role for the Braves who traded him away just three years ago.
Similarity Index 89
Hellickson appears here again.
Tapia is different in stuff than Almonte. Tapia is a fireballer with iffy command.
Maurer came out of no where this spring to win a spot in the Mariners rotation, but has been poor. He allowed 4 runs in 7 innings against the Royals back in May, striking out and walking no one.
Cortes was once a Royals Top-100 prospect who came over in the Mike MacDougal trade but then was shipped to Seattle in the Yuni Betancourt deal. Now a 26 year old reliever for the Padres AAA team.
Corbin was never a big prospect and was sent to the Diamondbacks as part of the Dan Haren trade, but 2013 saw him burst on the scene as he was a Cy Young candidate in the first half, winning 11 games with a 2.35 ERA, then cooling off in the second. 2014 is now a lost season as he's undergone Tommy John.
Greg Billo was a former Royal minor league who was just shipped to the Angels for "cash."
Pineda was once a in contention for one of the best pitching prospects in baseball and put together one of the best age-22 rookie seasons in 20 years, but was traded in the mega prospect challenge trade against Jesus Montero and Seattle/New York. Then in his first spring in a Yankee uniform he was scratched early on with a shoulder injury that would eventually lead to labrum surgery and a lost year.
All data is provided by Baseball Prospectus. Wikipedia describes Baseball Prospectus as "an organization that publishes a website, BaseballProspectus.com, devoted to the sabermetric analysis of baseball." This is a true statement. If you like true statements, specifically the one just stated, then you should subscribe to BP. Which you can do so here.