DIGGING DATA: The Uniqueness of Oneil Cruz

DIGGING DATA: The Uniqueness of Oneil Cruz

Surely one of the most interesting prospects in all of baseball is Pittsburgh Pirates 19-year old Dominican shortstop Oneil Cruz. Cruz is listed at 6’6″, 175 lbs. But Cruz isn’t a 3-and-D wing for the University of Kentucky basketball team, he’s one of the most promising hitting prospects currently playing in the A-Full Season South Atlantic League.

Cruz was originally signed by the Los Angeles Dodgers in the 2015 J2 signing period. He was traded at last summer’s trade deadline to the Pirates in exchange for left-handed reliever Tony Watson. Cruz is fascinating in many respects: he’s displayed an intriguing amount of speed for his 6’6″ frame, he has a cannon for a throwing arm (potential 80-grade), and despite the questions surrounding his hit tool, he’s posting a .289 batting average so far this season.

The biggest question that many prospectors have regarding Cruz is whether he can stick at shortstop as he fills out and moves up the ladder. While the limitations that a 6’6″ shortstop will have playing the field are pretty obvious, the Pirates seem open to at least trying to see if he can stick at the 6. Cruz has only played shortstop this season, starting all 85 games that he’s appeared in.

Obviously, I am as skeptical as anyone that a 6’6″ shortstop can make the plays necessary to be a good enough defender to play in the MLB. Shortstop is arguably the most difficult fielding position in baseball. Emphasis on the ‘arguably’. Sabermetric guru Tom Tango dug into the question of fielding position adjustments relative to WAR in the blog for his book aptly titled ‘The Book–Playing The Percentages In Baseball.’ In the end, the discussion generated the following defensive spectrum hierarchy:

Catcher: +12.5 runs (all are per 162 defensive games)
Shortstop: +7.5 runs
Second Base: +2.5 runs
Third Base: +2.5 runs
Center Field: +2.5 runs
Left Field: -7.5 runs
Right Field: -7.5 runs
First Base: -12.5 runs
Designated Hitter: -17.5 runs

Bear in mind that a defender generally moves up or down the spectrum one spot from his original position. Cruz might just be the exception to this rule though, as he’s highly unlikely to move to Catcher (although he probably has the arm for it), and a move to second base would seem to exacerbate the issues he’s having as a shortstop. Therefore, don’t be surprised if Cruz’s shift down the defensive spectrum takes him to third base or even right field.


For my money, the best way to determine where a young prospect will wind up on the defensive spectrum is to dig into some good old fashioned scouting reports. Baseball scouts are adept at judging a player’s reactions, footwork, fluidity, arm strength, and arm accuracy, and then distilling those skills into 2 tools: arm and glove.

John Calvagno got a couple looks at Oneil Cruz in June. Calvagno notes that Oneil Cruz is indeed a physical freak. “It’s safe to say I’ve never seen a player this long with this much athleticism on a baseball field.” Coming from John, who has seen and evaluated many players on a baseball field in his lifetime, this is quite a remarkable statement. Calvagno notes that Cruz’s lateral movement was good and his arm was indeed special (potential 80-grade). According to Calvagno, it’s not certain that Cruz will ever have to move away from SS, and the Pirates are likely to let him play there for the next several years to see if he can continue to handle the position as he moves up the ladder. The most likely landing spot for Cruz if he doesn’t stick at SS? Could be 3B, 2B, or even RF.

Adam McInturff of 2080 baseball has watched Cruz over the past couple years, and has noted that his defense continues to improve. He puts a 60-70 grade on Cruz’s arm, which he calls a ‘cannon’. Ultimately, McInturff thinks that Cruz will play a ‘corner’ defensively (1B/3B/LF/RF), but he also feels that his defense will be strong enough to keep Cruz off 1B.

Fangraphs lead prospect evaluator Eric Longenhagen has also been following Cruz. In a recent chat, Longenhagen likened Cruz to a ‘baby deer’, but he’s also heard evaluators say that they think he can actually stick at SS. Longenhagen puts his range of defensive outcomes down the defensive spectrum from SS->3B->RF. Fangraphs currently grades Cruz’s glove as 30 present/45 future and arm as 70 present/80 future.


Another concern with a prospect that’s built like Cruz is that his hit tool might lag because of the length of his swing. Cruz is what many baseball scouts refer to as ‘long-levered’. The midwestern expression I’d use to describe him is that he’s ‘all arms and legs’. I think these are terms that get at the fact that, because of his size, Cruz can appear to be slow to react or uncoordinated at times. The concern with a long-levered hitter is that his swing will get too long or loopy and he will be prone to striking out or making poor contact with the ball. Again, the scouts can give us some more insight to determine whether this categorization of Cruz is a fair one.

Going back to Calvagno’s scouting, he describes Cruz’s swing as long and linear (aka not ‘looping’). And then he gets to some fun stuff: Cruz displays plus bat speed, the swing is smooth, the ball ‘explodes’ off the bat, and his exit velos are ‘eye-popping’ with a present 70-grade raw power! Calvagno also notes that he’s ‘letting the ball travel deep’, meaning that he’s patient in his swing approach. To me, this is the sign of a player who has a plus hit tool.

Adam McInturff calls Cruz’s raw power grade 60/70. He also notes that Cruz has displayed more barrel control and that his hit tool is improving. The upshot of these scouting reports is that Cruz will be a valuable bat even if he winds up having to shift defensively to a corner OF position. If he can stick at 3B or, even better, SS, his value just goes up even more.


Pirates farm director Larry Broadway recently noted that Cruz has developed in one major way in 2018:

“The difference between this year and last year is now he actually has an approach. Last year, it was really just grip it and rip it. Now he’s going up there with a much better plan. He knows what he’s looking for in certain counts and he’s developed a two-strike approach. He’s really shown a lot more maturity as a hitter. He’s chasing a lot less—and it hasn’t cost him anything in terms of power.”

Cruz’s improved plate approach is being reflected in his numbers this season. I like to look for hitters who are ‘in control’ of the plate. Generally, these are hitters who have a small (less than 10%) K-BB%, have an ISO greater than .200, and display a batted ball profile where they hit more line drives + fly balls than ground balls (aka the green bean ratio).

Oneil Cruz Plate Control

K% BB% K-BB% ISO GB LD FB Green Bean
2017 30.1% 8.2% 21.9% 0.113 56.4% 16.0% 27.6% 1.29
2018 23.6% 7.8% 15.8% 0.195 52.2% 18.5% 29.3% 1.09

Cruz’s K-rate has improved. He’s now striking out at a 23.6% clip vs. a 30.1% clip in 2017. His walk-rate is essentially the same (8.2% in 2017 vs. 7.8% in 2018). His ‘plate control’ (K-BB%) still isn’t in the excellent range that I look for (10% or less), but it is improving (15.8% in 2018 vs 21.9% in 2017). And his ‘Green Bean’ ratio is changing for the better, meaning he’s hitting less ground balls as part of his overall profile. If his green bean dips below 1.0, we’d expect his slugging average to continue to rise. In short, Cruz’s offensive profile has improved this year, and it looks like a usable profile as he continues to mature and refine his approach.


Unfortunately, there is very little data on advanced defensive metrics at the minor league level. One statistic that is available for consideration is ‘range factor’. MiLB.com includes Bill James‘s ‘range factor’ in their individual player fielding statistics. ‘Range factor’ is an attempt to quantify a player’s defensive range by totaling the putouts and assists that he’s involved in and dividing them by the number of innings he’s played. Cruz’s range factor in 85 games at SS in 2018 is 3.53. The current MLB league average range factor at SS is historically above 4.0. So Cruz’s range is sub-standard. This is admittedly not a perfect defensive metric, but it does give you the idea that Cruz doesn’t have the range you would expect of an average shortstop.

Another defensive metric that’s readily available is fielding percentage. Fielding percentage takes a player’s total number of putouts and assists and divides them by his fielding chances (putouts+assists+errors). The MLB average fielding percentage for a SS is historically around .975. Cruz’s fielding percentage in 2018 is a dismal .912, and he’s committed 29 errors in 85 games. It’s safe to say that his statistical performance at SS this season shows that he will need to make some significant progress if he plans on sticking at SS in the future.


Oneil Cruz is a fun prospect unicorn to consider. Certainly, his physical stature and his statistical fielding performance to date scream that he’s a player who will need to be moved down the defensive spectrum and away from shortstop before he makes the majors. However, the scouting reports I’ve seen have noted that he’s a great athlete for his size and that Pittsburgh is going to give him a shot to stick at shortstop if he can handle it.

I think the offensive scouting reports and stats show that even if he moves down the defensive spectrum and away from shortstop, his bat could play well enough to make him valuable at 3B or a corner outfield position. He’s very much a work in progress, but his 2018 performance in Full-Season A ball as a teenager has shown that he’s capable of improving his plate approach in a way which can make him a more valuable fantasy contributor. He might not be the best prospect in the game, but he’s certainly one of the most interesting ones.

As a dynasty owner, I’d consider Oniel Cruz as a ‘hold’ asset generally. However, I’d be willing to trade him away in a deal which would help my team win this year. That being said, in 4-5 years you might regret trading away one of baseball’s most unique prospects.

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