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Cal Stevenson: Under-the-radar Blue Jays prospect with intriguing potential


Jays From the Couch look at another under the radar Blue Jays prospect that has some interesting potential- Cal Stevenson





Cal Stevenson was drafted by the Toronto Blue Jays in the tenth round of this year’s draft. A college senior, Stevenson wasn’t on any top prospect lists heading into the draft and ended up receiving a $5,000 signing bonus from the Blue Jays. The savings—his slot’s typical signing bonus was $140,200—helped the Blue Jays draft Adam Kloffenstein in the third round and sign him with a well above-slot bonus.


All that said, Cal Stevenson has the skills to develop into a much more useful player than his $5,000 bonus would imply. While he doesn’t possess a great deal of power, he has a great approach at the plate, has plus speed and is a strong defender in the outfield. He’s the sort of prospect one could see developing into a fourth outfielder at the major-league level. However, with his excellent plate approach, there remains the possibility that he could outperform expectations and develop into something more.


He certainly has his fans within the Blue Jays organization. Doug Fox recently spoke with Hunter Mense for Future Blue Jays. Mense was the AA New Hampshire Fisher Cats’ hitting coach this season and spent time working with newer Jays prospects at the fall instructs in Florida. He highlighted Stevenson as one of the more impressive hitters he saw, talking up Stevenson’s “advanced” plate approach.


Gil Kim, the Blue Jays’ director of player development, spoke glowingly of Stevenson at the fall instructs as well. In an interview with, Kim described Stevenson as “a polished player who controls the strike zone very well and has very good hand-eye coordination. He gets on base — probably one of our best baserunners in the organization — and anticipates on the base paths and in the outfield, where he can play all three spots. Apart from being a talented baseball player, he’s such a quality person, and I think that will continue to be a separator for him.”


Stevenson’s character is often brought up by those who’ve worked with him, something I discussed in a recent post on the kind of people the Blue Jays are trying to develop. While his ability to play baseball will ultimately determine his fate, his strong character is far from irrelevant. His ability to work well with coaches and adapt as a player will help him reach his ceiling.


Advanced plate approach

Stevenson’s resume as a pro is short, but impressive—he got on base in 56 of the 59 games he has played so far. It goes without saying that he will need to replicate his quality performances at the A-level and beyond before we should start picturing him playing at the Rogers Centre. But it also goes without saying that his performance this summer with the Appy League Bluefield Blue Jays was nothing short of exceptional.


Stevenson’s 173 wRC+ was the third-best mark among batters at the Advanced Rookie level in 2018 (min. 150 PA). Plate discipline was his main strength, with his walk rate (21.3%) leading the level and his strikeout rate (8.4%) fourth-best—his level-leading 2.52 BB/K was miles away from the next-best batter (1.67). His bat-to-ball skills were reflected in his .393 BABIP, which ranked in the 86th percentile. His power wasn’t as spectacular—he produced a .159 ISO, mainly thanks to doubles and triples—but it was still a bit above-average (60th percentile). In terms of the slash stats, Stevenson produced the level’s second-best batting average (.359), number one on-base percentage (.494) and 23rd-best slugging percentage (.518).


These marks also stand out when compared with all age-21 batters at the Advanced Rookie level since 2006 (499 such batters saw at least 150 PA in a single season). His overall production (wRC+) ranks twelfth-best in this group. He owns the second-best walk rate—after fellow Jays prospect Ryan Noda (2017)—and the seventh-best strikeout rate, so it’s not much of a surprise that his BB/K is tops by a long way (the next-best batter has a 1.80 mark). His BABIP (88th percentile) and ISO (61st percentile) this season both compare favourably to Advanced Rookie batters his age.


Very few whiffs, but lots of liners

When I wrote about Alejandro Kirk, Stevenson’s Bluefield teammate, I raved about his ability to avoid whiffs. In particular, his 5.1% whiff rate was the third-best mark at the level this season. Well, Stevenson’s 3.8% whiff rate was number one, not much of a surprise given his exceptional walk and strikeout rates. That his strong walk and strikeout rates are backed up by a super-low whiff rate makes me more confident that he’ll be able to maintain them as he progresses through higher levels.


In terms of the batted balls he generates, his calling card is the line drive—his 25.9% LD rate put him in the 89th percentile among Advanced Rookie level batters this season (min. 150 PA). When combined with his plus speed (more on that soon), those liners turn into doubles and triples at a healthy clip. Stevenson generates ground balls at a pretty average rate (45.9%, 47th percentile), but lags when it comes to producing fly balls (28.2%, 26th percentile).


Towards the end of the minor-league season, Eric Longenhagen included Stevenson in one of his Daily Prospect Notes. Longenhagen ended his blurb on Stevenson with a relevant note of optimism: “let’s keep an eye on this guy because Toronto has a track record of making swing adjustments to bat-first college players that have helped those players become more viable prospects.”


His plus speed is reflected in the numbers

In the same blurb, Longenhagen mentioned that scouts viewed Stevenson as having “plus speed”. At the minor-league level, there are a couple of stats used to help gauge a player’s speed. A player’s speed score (Spd) is an older sabermetric stat that provides an overall look at a player’s production as a runner. While UBR has supplanted it at the major-league level, data limitations mean that Spd is still useful for minor-leaguers. The FanGraphs version accounts for four factors: a batter’s stolen base percentage, frequency of SB attempts, runs scored per opportunity and rate of triples. Stevenson’s 9.0 Spd was tied for first among Advanced Rookie level batters in 2018, alongside teammate DJ Neal. The mark also ranks seventh among all age-21 batters since 2006 at the level.


A player’s wSB (weighted stolen base runs) focuses specifically on a batter’s ability to successfully steal bases (it is a component of UBR). In a nutshell, runners are credited with 0.2 runs for a successful steal and docked about 0.4 runs when they’re caught. This season, Stevenson’s 3.5 wSB (the result of 20 successful steals and only one unsuccessful attempt) ranked second at the Advanced Rookie level. Going back to 2006, Stevenson’s mark ranks fifth among age-21 players.


His defence opens up a few paths to the majors

In addition to his success as a hitter and a runner, Stevenson showed off quality defence in the outfield as well. His primary position this season was left field, where he got 30 starts. Clay Davenport assigned him a +10 FRAA for his defence there, by far the best mark in the Appy League. He also got 19 starts in centre field, where he produced +3 FRAA. In spite of the small sample size, that mark was tied for third-best in the league.


One can envision a few reasonable paths for Stevenson to get to the big leagues. Thus far, he’s shown an ability to play all three positions (something Gil Kim echoed in the aforementioned interview). If his plate production diminishes to just below-average as he progresses through the upper minors, that ability to play across the outfield (as well as his strong base running) could allow him to stick as a fourth outfielder. In the context of a tenth round draft pick, that kind of outcome is a success.


If his hitting holds up relatively well at higher levels, his excellent LF defence (and base running) would give him a good shot at being a MLB regular. A best-case scenario would see him maintain roughly average CF defence alongside above-average offence, in which case he’d be an MLB regular at a premium position.


Given his low draft stock, it will take more than 249 (phenomenal) plate appearances at the Advanced Rookie level to get people to buy into his big-league potential. Next season, he will face tougher challenges, likely at the Low-A level to start, which will reveal a great deal about his true potential. The glowing reports of his personality certainly make him an easy prospect to cheer for through his journey.


If 2018 represents his pinnacle as a prospect, then he deserves kudos for putting together such an extraordinary campaign. That said, when I look at his plate discipline, bat-to-ball skills, base running and defence, I can’t help but see a prospect who just might be a diamond in the rough.





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Jeff Quattrociocchi

I'm an economics professor in the GTA whose lifelong love for the Jays was reignited by that magical August of 2015 and the amazing moments since.