Fangraphs loves Blue Jays’ Danny Jansen (and other cool stuff)


Toronto Blue Jays catching prospect, Danny Jansen, is garnering  a great deal of attention, with good reason


Embed from Getty Images


Danny Jansen‘s 2017 exploits are by now well-known among Blue Jays fans. After getting healthy and wearing corrective lenses, Jansen started hitting. And kept hitting, all the way from High-A to AAA, one jump away from the big leagues. At each stop, Jansen ranked highly in wRC+, cracking the Top 5 in High-A and AAA and the top 25% of batters in AA.



Chris Mitchell, developer of Fangraphs’ KATOH projection system (more on that later), found that (from High-A up to AAA) three stats are key indicators of big league success: a player’s strikeout rate, ISO and BABIP. In terms of ISO and BABIP, Jansen produced average or better marks at all three levels. But where his MLB potential stands out is in avoiding strikeouts—he ranked no worse than 13th in strikeout rate in each of the three levels he played at in 2017.



Danny Jansen rarely swings and misses

Even more impressive is his ability to avoid whiffing on pitches. Minor league whiff rate data is relatively new, so it wasn’t included in Mitchell’s KATOH research. But, it seems intuitive that an excellent whiff rate in the upper minors would be a very good indicator of big league success, at least in terms of plate discipline. It’s one thing to have average power numbers when you’re swinging and missing at every ball you don’t hit out of the park. It’s another thing altogether to hit for decent power and contact, as Jansen did at all three levels, while almost never whiffing on a pitch. After producing a High-A-best 3.5% swinging strike rate, he managed to improve upon that mark in each of his two promotions.


His 3.1% whiff rate at AAA in his age-22 season is nothing short of extraordinary. In 2017, across the AAA level, only seven players aged 21 or 22 cracked the top 170 in swinging strike rate (minimum 70 PA). Each of them was viewed by at least one outlet as a Top 100 prospect. Intuitively, it seems that only very, very good prospects produce low whiff rates in their early-20s at the AAA level. Sure, one can quibble with Jansen’s small sample size. But, his equally low whiff rates at High-A and AA should dispel any concerns that this was driven by luck over a small sample size. Jansen showed elite eye and batted ball abilities throughout 2017. He also had success in 2016 at High-A, where he posted a 6.4% whiff rate (217 PA, 28th lowest).



Jansen’s 3.1% swinging strike rate at age 22 playing for the AAA Buffalo Bisons was historically exceptional. This stat is available on Fangraphs for the minor leagues as far back as 2008. Since 2008, no batter, aged 22 years old or under, kept a whiff rate lower than Jansen’s at the AAA level (minimum 70 PA). Two Clevelanders did have notable performances. At the age of 22, Jose Ramirez (2015, 195 PA) posted a 3.2% whiff rate, while Michael Brantley (2009, 528 PA) posted a Jansen-matching 3.1% whiff rate.


Michael Brantley might be a useful comp for Danny Jansen

Brantley was the only 23 year old to beat Jansen, posting a 2.1% whiff rate in 2010 (316 PA). [Only 20 batters over the age of 22 posted sub-3.1% whiff rates over the last ten seasons, so it’s an accomplishment even without the context of his young age.] Take the following with a grain of salt, because one point of data (Brantley) can’t predict the future (Jansen). Brantley seems like a good comp to have in mind, hitting-wise, when thinking about Jansen’s future. In particular, one of the more realistic best-case scenarios.



Let’s start with whiff rate, the tie that binds these two players most. Jansen’s 2017 MiLB whiff rate limits the likelihood that Jansen’s small sample size AAA whiff rate is not an accurate reflection of his ability. Michael Brantley posted a similar AAA whiff rate and was able to maintain it across his major league career. Since his 2009 debut, he possesses the 8th lowest whiff rate in the majors among 519 qualified batters. Brantley’s low MLB whiff rate was the result of both an aversion to chasing pitches (23.9% O-Swing%, 73rd lowest) and good bat-to-ball skills (91.2% Contact%, 7th highest).


Examining that group of players, I found that SwStr% is most strongly correlated with K% (R2 of 0.71). On average, a 1% increase in a batter’s whiff rate correlates to a 1.5% increase in their strikeout rate. Whiff rate is also somewhat correlated with ISO (R2 of 0.27). On average, a 1% increase in whiff rate correlates to a .008 increase in ISO. Intuitively, power hitters tend to be more aggressive, leading to more big swings and misses.


We see these two correlations over Brantley’s AAA and MLB career. His K% is stellar, 26th lowest in the majors since 2009, but his ISO is a bit light, ranking 363rd. His good plate approach overall helped him maintain an above-average BABIP and an average walk rate. The result was above-average hitting production, with his 112 wRC+ ranking 111th in the majors.


Brantley’s career offers a template of a player who carried the same exceptional talent that Jansen has shown in the minors into the major leagues. A low whiff rate seems like a sustainable skill. This would suggest that Jansen could carry a low K% into the majors. If he can also maintain even slightly below-average power and slightly above-average walk rate and BABIP, you could envision him becoming a solid major league hitter overall (with a wRC+ in the 105-115 range).


The big prospect evaluators started to notice Jansen in 2017

His 2017 performances fuelled a dramatic rise in his prospect ranking. He was rated the 7th best Blue Jay prospect by both Baseball America and Baseball Prospectus, and ranked 8th among all catching prospects by MLB Pipeline.


Fangraphs is another site high on Jansen, arguably even more so than the others. What stands out about Fangraphs is the sheer number of independent projection systems it publishes, four of which rate Jansen as likely to contribute at the MLB level, both now and in the future.


2018 Fangraphs Projections

Two of these methods focus on the short-term: the 2018 season. The Steamer projection system was created by Jared Cross, Dash Davidson, and Peter Rosenbloom. Steamer presents its projections in a couple of ways: with a realistic amount of playing time assigned to each player and with all players performances pro-rated across 600 PA (450 PA for catchers).



Given that Jansen appears to be the second-best catcher in the Blue Jays entire system (after Russell Martin), their realistic projection of his playing time sees him getting 134 PA. In those appearances, Jansen is expected to produce roughly average hitting production for a big league catcher. While he’s expected to produce extra-base hits and turn balls in play into base hits less often than the average catcher (low ISO and BABIP), he’s also expected to have much better plate discipline than the average major league catcher (high BB/K).


Driven by a combination of average hitting (for a catcher), average base running (0 BsR) and average catching defence (about 0.3 defensive runs above average before a positional adjustment is applied), Jansen is expected to produce 0.5 WAR in 2018 in a backup role. That mark would have ranked him 38th in the majors among catchers last season, even with Roberto Perez and Carlos Ruiz and ahead of plenty of others—28 catchers saw 100+ PA in 2017 and produced less than 0.5 WAR. Compared to other catchers’ 2018 Steamer projections, Jansen ranks tied for 40th, alongside Carson Kelly (MLB Pipeline’s #2 catching prospect).


Additionally, Steamer provides a prorated version of their projection, with all players on equal playing time (450 PA for catchers). A grain of salt is needed with these projections, as a player (especially a rookie) is unlikely to maintain the same rate stats over 134 PA as they would over 450 PA. Nevertheless, with that caveat in mind, the Steamer 450 projections allow us to compare catchers in a more apples-to-apples kind of way. Across 450 PA, Danny Jansen projects to produce 1.8 WAR. In 2017, 1.8 fWAR would have ranked tied for 18th among all catchers, alongside Toronto’s own Russell Martin (though he did it in 365 PA).


In this case, we have the Steamer 450 projections for all catchers (not the case yet with the next projection system), so we can also compare Jansen’s 2018 projection to those of other catchers. Jansen is tied for 28th in projected WAR, alongside Chance Sisco (top Orioles prospect). [Of relevance to Jays fans, Steamer 450 projects Martin to produce the 4th highest WAR among catchers in 2018.] In terms of Jansen’s specialty, plate discipline, Steamer projects him to have the 8th highest BB/K among MLB catchers in 2018.


Fangraphs also publishes Dan Szymborski’s ZiPS projection system. [While the full dataset has yet to be published, data for each team is currently available.] ZiPS is a little less bullish on Jansen than Steamer is, but it’s only a matter of degree. In 416 PA—note that ZiPS doesn’t intend to produce realistic playing time predictions, so this shouldn’t be viewed as the system’s expectation of his 2018 PA total—Jansen is projected to produce 1.2 zWAR. This production is driven by hitting and catcher defence that is a little below average (projected BsR is not included in the ZiPS team projections, but should be available once the full dataset is rolled out). A mark of 1.2 fWAR would have been good for a tie for 25th among catchers in 2017.


For added context, let’s compare Jansen’s 2018 projections to that of Cleveland’s Francisco Mejia, the consensus #1 catching prospect in the MLB—rated #1 among catching prospects by MLB Pipeline, Baseball America and Baseball Prospectus.



It is not my intention to suggest that Jansen and Mejia are equals. Obviously, I’m simply scouting the numbers here (in particular, projections of performances that haven’t happened yet) and there’s significant value in considering scouting grades. For example, MLB Pipeline placed a 60 FV on Mejia and a 50 FV on Jansen.


Nevertheless, based on 2018 Steamer 450 and ZiPS projections, Jansen compares very favourably to Mejia. Steamer views the two as roughly equally productive hitters, though Jansen’s value comes from his plate discipline, while Mejia’s comes from his batted ball performance (both in terms of power and contact). However, Steamer gives Jansen a big edge in defence, which drives his higher WAR projection. This seems reasonable, as MLB Pipeline alludes to Jansen having superior catching skills than Mejia—Jansen has a higher fielding FV (50) than Mejia (45) and they report that Mejia spent his entire time in the 2017 Arizona Fall League playing third base.


ZiPS paints a fairly similar picture, but assigns them the same defensive runs, which results in the two sharing the same zWAR. The fact that two objective projection systems view the two prospects so similarly in 2018 (and in one case gives Jansen the edge) is a very positive sign for Danny Jansen.


Long-term Fangraphs Projections

Fangraphs also provides a couple of long-term projections of a prospect’s quality. This year, Eric Longenhagen and Kiley McDaniel worked together to produce good, old fashioned scouting grades for MLB prospects. While their team-by-team lists are still being published (with the Jays list still due), the duo recently published their Top 100 list. While Jays fans had gotten used to seeing Vlad Guerrero Jr., Bo Bichette and Anthony Alford on these lists (with Nate Pearson occasionally included as well), we were pleasantly surprised to find Jansen’s name pop up as well.


He was ranked third among catchers, after Mejia (listed as a C/3B) and the Dodgers’ Will Smith. Like MLB Pipeline, Longenhagen and McDaniel assign Jansen a 50 FV, with a variance of “low” implying that it’s a good bet he’ll meet those expectations. A 50 FV means he is expected to become an MLB regular, capable of producing 2 WAR per season. Their summary mentioned that “he is difficult to strike out and should reach base plenty” and suggested that “he’s a near-ready everyday catcher”.



The tool grades reflect much of what we’ve seen so far in the short-term projections. He’s got an above-average plate approach, average power that he hasn’t yet fully tapped in to and roughly average catching abilities. The relatively small gap between his tools’ current and future values reflects the low variance label Fangraphs gave him. He’s just about ready to be a good MLB catcher.


Fangraphs also publishes a stat-based long-term projection system, the aforementioned KATOH. The system uses minor-league data to project a player’s production over their first six years in the majors (the years before he hits free agency). Last July, the mid-season KATOH Top 100 list had Jansen ranked 81st, projected to produce 5.1 WAR over his first six MLB seasons. That was the first time (to the best of my knowledge) that Jansen was rated among the game’s top prospects by any of the major sites.


Recently, the 2018 KATOH Top 100 list was published. This time, Jansen jumped up to 51st, though his projected WAR was unchanged at 5.1. Mejia, on the other hand, saw his stock fall some since those mid-season rankings. Last July, he was projected to produce 8.0 WAR over his first six seasons. Now, that projection has fallen to 6.7 WAR. KATOH loves Carson Kelly though, projecting him to produce 12.1 WAR in his early career.


Let’s try to add further context to Jansen’s 5.1 WAR projection. First, let’s assume that he takes over the backup role for the Jays in 2018, takes on a more prominent backup role in 2019 and then runs with the starter’s job for four seasons. These would represent his age 23 to 28 seasons. A 5.1 WAR stretch would rank 45th among all catchers since 1995 who were in their age 23 to 28 seasons. The soon to be released Fangraphs Blue Jays prospect list will include more detailed KATOH information (click here to see the Blue Jays KATOH projections from 2017). This includes the likelihood that Jansen will end up near the top of the table below, the middle, around his KATOH projection of 5.1 WAR or any of the various possibilities below that.



Let’s wrap things up with a reminder that everything I’ve said in this post comes with the understanding that there is a huge amount of variance in the possible futures of a given prospect. Jays fans are hopeful that Jansen meets or surpasses each of these projections, but understand that he may not. The primary intention of this post is to highlight just how positively Danny is viewed by Fangraphs, both in terms of objective systems and subjective scouting grades.


Like I pointed out before, while other prospect sites didn’t include Jansen in their Top 100 lists, they are all still pretty high on him, thinking enough of him to include them in their top Blue Jays or catcher prospect lists. All of this suggests that the Jays have a special player on their hands in Danny Jansen, made especially special by his meteoric (yet seemingly sustainable) rise in 2017. A special player who may be ready to contribute at the big league level in 2018. A special player who may be able to produce quite effectively for years to come.




*Featured Image Credit: R Widrig- JFtC






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.