The Red Sox acquired a second pitcher on Tuesday following their trade for reliever Tyler Thornburg — in this case, receiving talented left-handed starter Chris Sale from the White Sox in exchange for an impressive return (roughly in order of consensus future value): Yoan Moncada, Michael Kopech, Luis Alexander Basabe and Victor Diaz.

Here’s how the minor leaguers headed to Chicago grade out by my KATOH system. KATOH denotes WAR forecast for first six years of player’s major-league career. KATOH+ uses similar a methodology with consideration also for Baseball America’s rankings.


Yoan Moncada, 2B (Profile)

KATOH: 6.2 WAR (38th overall)
KATOH+: 14.0 WAR (4th overall)

There’s no denying that Yoan Moncada was one of the most productive hitters in the minors this year. In 61 High-A games, he hit .307/.427/.496. In 44 Double-A games, he slashed .285/.388/.547. He 45 stolen bases across both levels. Moncada excels in multiple areas: he hits for power, runs like crazy, and plays a semi-premium position. His tools are top-notch, which is why he was the consensus No. 1 prospect last summer.

Moncada’s an exciting player, and if there’s one think I hate being, it’s a Debbie Downer. But I wouldn’t be doing my job if I didn’t point out that KATOH isn’t particularly crazy about Moncada. It sees him as a very good prospect, but definitely not the best in baseball. For all his strengths, Moncada has one major statistical flaw: strikeouts. In Low-A in 2015, Moncada struck out 23% of the time. Last year in High-A, he whiffed in 21% of his trips to the plate. Both of those numbers are concerning, but they’re nowhere close to alarming. His 31% clip from Double-A, however, is much closer to alarming.

As we all know, big-league pitching is much better than Double-A pitching. So if a hitter experiences trouble making contact against Double-A pitchers, it’s pretty likely that he’ll have even more trouble in the big leagues — at least right away. For this reason, KATOH likes guys who can make contact. Moncada compensates for his lack of bat-to-ball skills by excelling in a number of other areas, but not enough to profile as a super-elite prospect in KATOH’s eyes, especially when Baseball America ranking isn’t taken into account.

There’s also the matter of Moncada’s defense. He’s primarily played second base since emigrating from Cuba, and the prognosis for low-minors second basemen isn’t great. The fact that he’s already been deemed “not a shortstop” is a knock against him in KATOH‘s eyes. Furthermore, his defensive metrics at second base aren’t great. He was six runs below average this year by Clay Davenport’s fielding data, which suggests he may not be long for the infield.


To put some faces to Moncada’s statistical profile, let’s generate some statistical comps for the toolsy Cuban infielder. I calculated a Mahalanobis distance between Moncada’s performance this year and every High-A and Double-A since 1991 in which a second baseman or third baseman recorded at least 400 plate appearances. In the table below, you’ll find the 10 most similar seasons, ranked from most to least similar. The WAR totals refer to each player’s first six seasons in the major leagues. A lower “Mah Dist” reading indicates a closer comp.

Please note that the Mahalanobis analysis is separate from KATOH. KATOH relies on macro-level trends, rather than comps. The fates of a few statistically similar players shouldn’t be used to draw sweeping conclusions about a prospect’s future. For this reason, I recommend using a player’s KATOH forecast to assess his future potential. The comps give us some interesting names that sometimes feel spot-on, but they’re mostly just there for fun.

Yoan Moncada’s Mahalanobis Comps
Rank Name Mah Dist KATOH+ Proj. WAR Actual WAR
1 Carlos Febles 6.4 10.4 2.0
2 David Wright 10.7 9.1 36.8
3 Mike Kelly 11.1 7.8 1.1
4 Todd Walker 11.6 11.1 4.6
5 Andy Marte 13.3 10.2 0.3
6 Michael Cuddyer 15.2 10.1 7.8
7 Edwin Encarnacion 16.1 7.7 7.4
8 Brendan Harris 17.9 7.7 3.4
9 Marcus Giles 18.6 10.0 17.8
10 Adam Piatt 19.8 12.1 1.1


Michael Kopech, RHP (Profile)

KATOH: 9.2 WAR (13th overall)
KATOH+: 7.7 WAR (29th overall)

To say Kopech dominated this year would be an understatement. In 11 starts at the High-A level, the 6-foot-3 righty struck out a jaw-dropping 40% of batters on the way to a 2.25 ERA. On the downside, he also put up an unsightly 14% walk rate. It’s never a good thing when a pitcher allows that many walks, but by my math, the good far outweighs the bad.

As a 20-year-old with less than a half-season in High-A under his belt, Kopech is likely a year or two away from becoming big-league ready. This adds some risk to his profile. In a vacuum, KATOH likes safe bets, not pitchers who are far away. But Kopech’s 2016 performance was great enough to convince my computer he’s for real.

Unlike with Moncada, KATOH likes Kopech much better than Baseball America did at midseason, when they ranked him at No. 93. As a result, adding prospect rank into the mix actually drags down his projection. But given Eric Longenhagen’s encouraging writeup, it’s fair to question whether Kopech’s midseason ranking is a good data point.


Michael Kopech’s Mahalanobis Comps
Rank Name Mah Dist KATOH+ Proj. WAR Actual WAR
1 Jose Arredondo 4.9 4.0 1.2
2 Mike Judd 5.6 4.8 0.2
3 Erik Bedard 6.1 4.2 18.2
4 Bartolo Colon 6.1 8.6 26.2
5 Jake Peavy 6.3 8.5 29.8
6 Chad Billingsley 6.3 6.6 19.4
7 Clint Nageotte 7.2 4.4 0.0
8 Rick Huisman 7.3 5.9 0.1
9 Jaret Wright 7.7 5.3 9.7
10 Rafael Orellano 7.9 3.8 0.0


Luis Alexander Basabe, OF (Profile)

KATOH: 2.6 WAR (243rd overall)
KATOH+: 2.2 WAR (302nd overall)

Basabe put up some flashy numbers in his full-season debut last year, pairing 12 homers with 25 steals. His 26% strikeout rate is something of a concern, though, as it suggests he may not hit enough to make it work at the upper levels. Basabe’s an interesting prospect, but KATOH will need to see a bit more before it gives him a realistic shot of making a big-league impact.


Luis Basabe’s’s Mahalanobis Comps
Rank Name Mah Dist KATOH+ Proj. WAR Actual WAR
1 Chris Young 7.7 2.9 15.2
2 Noochie Varner 7.8 2.2 0.0
3 Jordan Schafer 8.5 1.4 2.1
4 Rick Asadoorian 9.9 1.2 0.0
5 Steve Moss 9.9 1.2 0.0
6 Jose Duarte 10.1 1.1 0.0
7 Dewayne Wise 10.2 1.9 0.4
8 John Shelby 11.1 3.1 0.0
9 Javier Herrera 11.2 1.8 0.0
10 Henri Stanley 11.7 1.1 0.0


Victor Diaz, RHP (Profile)


Diaz pitched decently as a Low-A reliever last year, but so did dozens of other guys you’ve never heard of, and probably never will. The fact that he’s already 22 is another strike against him. He throws hard, which makes him easy to dream on, but KATOH is very unimpressed with his results so far.