If They Hit, Diaz & Solarte are Both SS Options for Blue Jays


With the questionable health of Tulo, Jays From the Couch explores shortstop options for the Toronto Blue Jays


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Let me immediately clarify what I mean by “hit”. Aledmys Diaz and Yangervis Solarte do not need to be among the best hitters in baseball. They do not need to have career years. With their general level of shortstop defence and base running ability, either of them has the potential to be league-average everyday shortstops with career-average seasons at the plate. This post will dig into the assumptions required to get them there and make the case that either of them can fill in for Troy Tulowitzki for an indefinite period of time.


Diaz’s Shortstop Defence

First, let’s establish defensive expectations for each of them at shortstop. This task is pretty straightforward for Diaz. He has played just shy of 1500 innings at short as a big leaguer, producing a -8 UZR/150 (I’ll be sticking with UZR in this post as Fangraphs uses it in their fWAR calculation). That is not great SS defence—among shortstops with 1000+ innings over the last two seasons, Diaz ranked 28th out of 33 in UZR/150. However, it’s always important to put defensive performances at premium positions in their proper context, using positional adjustment. In terms of Fangraphs’ Def/150, Diaz (-1.2) ranked 138th of 267 players (minimum of 150 games over the last two seasons), just below the league average.


Solarte’s Shortstop Defence

With Solarte, estimating his defensive acumen at shortstop is much trickier. He has played only 200 or so innings there as a major leaguer, producing a 7.9 UZR/150 over that time (a mark that nobody would assume captures his true talent at SS). However, he has played just over 1000 innings at 2B and just over 2500 innings at 3B, the two positions most comparable to shortstop. Over fairly large sample sizes, he has produced a UZR/150 at each position that is just a smidge below-average—among 46 second basemen with 1000+ innings played there since 2014, his -1.7 UZR/150 ranked 28th, while his -1.2 UZR/150 ranked 29th among 52 third basemen meeting the same requirement.


So, in order to produce a (somewhat realistic) estimate of Solarte’s defensive abilities at shortstop we will need to get creative. First, let’s get an idea of where Solarte’s full, position-adjusted body of work ranks among those with some experience at shortstop. There are 84 major-leaguers who saw 600+ PA from 2014-2017, while also playing 100+ innings at shortstop. Among these fielders, Solarte’s -0.52 Def/150 puts him in the 24th percentile (well below-average, but not terrible).


Let’s assume that Solarte’s defensive abilities would rank him in the 24th percentile among shortstops. Is that generous for a guy with limited experience there? Perhaps, but he was much better-than-average in his SSS at SS and he has displayed just below-average skills at 2B/3B, so I don’t believe that’s an absurd estimate of his hypothetical percentile rank among shortstops (after all, I’m not talking about moving Kendrys Morales over to short or anything). Over the last decade, 265 players have seen at least 700 innings (or about a half-season’s worth) of action at shortstop in a single season. In terms of UZR/150, Derek Jeter’s 2010 season (-5.1) ranked in the 24th percentile. [The advanced stats really hated Jeter’s defence at short. That mark was the 5th best UZR/150 of his career. Only once did he post a positive UZR.]


Interestingly, we can get to the same number (Solarte maintaining a -5 UZR/150 at SS) using a different method. Over his career, he has been just worse than -1 UZR/150 at 2B and 3B. Studies using older data implied that playing shortstop is five runs per season “harder” relative to second and third base. Newer data suggests that the difficulty gap is closer to three runs per season.  If we split the difference (and assume that playing SS is four runs harder than 2B or 3B), then Solarte’s defensive performances at 2B and 3B imply that he should generate a UZR/150 of about -5 at SS.


Key Assumptions

At this point, let’s work backward to find the level of hitting production that each potential Blue Jay shortstop would need to maintain this year in order to be considered league-average at his position. First, how much fWAR is league-average for a shortstop anyways? The exact number depends on how you approach the question, but a range of 1.8 to 2.2 fWAR seems about right.


Shortstops (as a group) produced 1.8 fWAR per 600 PA in 2017. This is a nice, clean estimate but includes second- and third-string shortstops. Focusing only on everyday shortstops increases the average a little bit, to 2.2 fWAR. This average can be found in a couple of ways. Looking back to 2017, if we focus on the 30 shortstops with the most plate appearances (minimum of 385) and rank them in terms of fWAR/600 PA, the 15th best mark is 2.2 (Addison Russell). Looking ahead to 2018, via the Steamer 600 projections, the 15th highest projected fWAR/600 PA is also 2.2 (Jose Iglesias). Let’s be conservative and assume that a league-average, everyday shortstop produces 2.2 fWAR for every 600 PA.


Second, what is a fair estimate of their base running production? While Depth Charts projects them both to be worth about -1 BsR/600 PA in 2018, I’m going to take the conservative route again and use their career marks (-2.5 for Solarte and -3.2 for Diaz).


Hitting Production

With all of the assumptions in place, their “target” hitting production becomes clear. For Diaz, his below-league-average defence and base running require him to produce a .335 wOBA in order to reach a mark of 2.2 fWAR. In Solarte’s case, his slight edges over Diaz in terms of both defensive and base running production lower his target to a .328 wOBA.



So, how doable are these two targets? Well, Solarte is projected by both Steamer (.331) and ZiPS (.329) to meet his target. His strong hitting is a key reason why I think he’s got a chance to stick at shortstop for an extended period of time. Over the last ten seasons, the average shortstop has produced a wOBA of .305 (with a range of .297 to .315). Solarte’s career wOBA is .324. In 2017, Solarte’s career-low wOBA of .311 was still better than the average shortstop’s (.309).


If we opt for a more conservative view of Solarte’s hypothetical shortstop defence, his hitting target increases. Let’s say that Solarte is only able to match Diaz’s defence. In order to produce 2.2 fWAR over a full season at short, Solarte would need to produce a .334 wOBA. That is a mark he’s only achieved once over a full season and .010 above his career-average—doable, but tricky. However, if he were to hit for a (more realistic) .328 wOBA and manage a -8 UZR/150 at short, he’d be looking at a fWAR of about 1.9, which is still solid (the Pirates produced 1.9 fWAR out of SS last season, good for 17th in the majors). Solarte is a good enough hitter that he can provide the Jays with crappy, but playable defence at short and they still wouldn’t be losing much.


In Diaz’s case, the situation is a bit more complicated (Solarte’s much more clearly established hitting production is a key reason why I’ve included him in this exercise). By now, we all know the story: an all-star in 2016 (.370 wOBA), demoted to AAA in 2017 (.291 wOBA). For one thing, Diaz swung at a lot more pitches outside of the strike zone in 2017, which contributed to his halved walk rate. A dramatic fall in his batted ball performance is also evident.



The big question is whether Diaz is a candidate for a bounce-back season. In terms of simply bad luck becoming neutral, the answer is no. There were fundamental regressions in his performance last year that must be remedied. My guess is that the Blue Jays acquired him with the informed opinion that they could “fix him”. Mike Sonne highlighted his 2016 hand injury as a possible reason for his 2017 struggles at the plate.


Let’s return to Diaz’s “wOBA target” of .335. The hope for Diaz is that while his 2016 performance was excessively fortunate, his 2017 performance was excessively unfortunate. If his overall career performance (.338 wOBA) is an accurate gauge of his talent, that target is very doable. Ultimately, that is a big “if”. What if he simply meets his projections for 2018? Well, they highlight the uncertainty around his hitting—on the low end, ZiPS projects him to produce a .304 wOBA (a little bit worse than the average shortstop), while Steamer puts him at a .319 wOBA (a little bit better than the average shortstop). If he’s limited to the ZiPS projection, he will only produce 0.6 fWAR. If he matches the Steamer projection, the resulting 1.4 fWAR/600 would have put him 21st among everyday shortstops in 2017.


Concluding Thoughts

This exercise has led me to an unexpected conclusion. In my opinion, Solarte might actually represent the lower variance option at short, in spite of his limited experience at the position. He has to be one of the most consistent batters in the majors, with his four seasons ranging from slightly below-average (93 wRC+ last year) to solidly above-average (119 wRC+ in 2016). I examined his consistency by looking at all batters who had 300+ PA in each of the last four seasons, focusing on how much variation there was between their wRC+ in each of the four seasons. Solarte had the 35th lowest wRC+ standard deviation among 130 qualified batters, suggesting that he is amongst the most consistent batters in baseball. Plus, in lieu of shortstop experience, he has seen just over 3500 innings of action at second and third base.


The team clearly views Diaz as their primary shortstop heading into the season, with his 61 Spring Training innings at short comfortably number one (as of Friday). However, while Gift Ngoepe (36 innings) and Richard Urena (32 innings) are each getting good looks there, the fact that Solarte has found himself at shortstop for 14 innings this season suggests that the Jays aren’t totally writing off the possibility of putting him in for Tulo, at some point. For context, Solarte hasn’t seen any Spring Training action at shortstop since his rookie season (2014). Obviously, the team will justifiably give Diaz the first shot out of the gate. And, it goes without saying that the team is best off if Diaz takes his opportunity at shortstop and runs with it, leaving Solarte for the super-utility role he was acquired to fill. However, I do feel at peace with the idea that Solarte could effectively handle the shortstop position, if necessary. Is it a role I envision him in for the Blue Jays for years to come? No. But he (and Diaz) look like a good duo to fill in for Tulo while he’s rehabbing.




*Featured Image Credit: C Stem- 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.