If the Nationals don’t add another starting pitcher by the time Spring Training rolls around, then it’s likely that Joe Ross claims the fifth spot in the team’s rotation. Ross debuted last season, making 13 starts and three relief appearances, after just 24.2 innings at Triple-A. In those 13 starts, he was excellent, striking out 22.5% of the batters he faced, while walking just 6.6% of them. He also induced grounders at a strong 49.5% clip, which paired with his strikeout and walk rates, resulted in a 3.61 SIERA. The showing has unsurprisingly already led to some preseason sleeper love. As I continue to work through my Pod Projections, I have come to the realization that I both love and hate Ross, similar to how I felt about Carlos Martinez last preseason.

So let’s run through the positives and the negatives…

The Good

Oh, That Slider — Ross threw his slider 35.6% of the time and it generated a ridiculous 25.8% SwStk%. That is elite, as Eno found two years ago that the average slider induced a SwStk% of 15.2%. Furthermore, according to Baseball Prospectus’ PITCHf/x leaderboard, Ross induced a Whiff/Swing rate on the pitch that ranked eighth highest among pitchers who threw at least 200 sliders.

Are you convinced yet that this was one wicked pitch? No? Good. Because there’s more. The pitch also generated a ground ball rate nearing 55%, well above the league average, which is just shy of 44%.

“Explosive” Fastball — It’s the term Kiley McDaniel used to describe Ross’s fastball, which is a sinker (PITCHf/x indicates he threw a four-seamer just 5.1% of the time, and the sinker 53.2% of the time). Kiley also characterized the pitch as having “plus life”, which is necessary to get that sinking action to generate all those ground balls. The pitch averaged about 93.3 mph and peaked at 97.4 mph. That’s quite the hard sinker! It generated grounders at a 51.3% clip and surprisingly even a whole lot of pop-ups as well (20.7%).

Worm-Killing SkillZ — Both the slider and sinker generate lots of ground balls. Ground balls are good because they can’t go for a home run, except in those rare inside-the-parker varieties which typically requires a defensive misplay.

Above Average Control — Ross pumped in strikes 65.1% of the time, versus a 64.3% league average. He sports a career minor league walk rate of about 7.0%, so the good control he brought with him to the Major doesn’t seem like a fluke.

The Bad

But is that Slider For Real? — I’m no scout and have never tried to impersonate one, so I rely on others’ scouting reports, believing them to paint a reasonable picture of a pitcher’s repertoire. Heading into the 2015 season, Kiley slapped a 45/55 (Present Value/Future Value) grade on Ross’ slider and noted that he had heard future grades range from 45 to 55, with flashes of 60, and that most scouts agree it’s a future average to slightly above pitch. In no way does that description jibe with the results of the pitch during his short time in Washington last season. So that means one of three things:

A) The scouts were wrong and their eyes deceived them; perhaps the pitch doesn’t look all that fantastic, but it just gets the job done.

B) The scouts were right and the results are unsustainable and built on a rather small sample size which we cannot draw too much significance from. The results of Ross’ slider will be significantly worse in 2016 and better match the scouting reports.

C) The scouts had been right, but no longer are, because Ross improved his slider dramatically during his time down on the farm in 2015.

I have no way of researching C), but it’s a plausible explanation. Young pitchers improve their pitches all the time and end up better than anyone ever expected. I don’t know which answer is the correct one, but that there are three possible scenarios means we cannot automatically take his slider results like gospel and claim he has one of the best sliders in baseball.

That So-Called “Explosive” Fastball — So remember when I gushed about Ross’ sinker above? Yeah, well it’s supposed to be elite, but so far the results haven’t exactly been there. The average sinker generated a 49.5% ground ball rate, so a 51.3% clip is nothing special. If it displayed explosive life, you would perhaps expect a higher mark.

Furthermore, it was not a very good swing and miss pitch. The average sinker has generated a SwStk% of 5.4%, but Ross’ was just 4.2% last year. You would hope it would perform extremely well in either the ground ball or swinging strike departments, but it’s just average at the former and actually well below average at the latter. Maybe the 65/70 grade fastball shows up this year and the pitch’s ground ball and SwStk% both rise, pushing the pitch into elite territory. Or maybe it remains just mediocre.

Sinker, Slider, and…??? — We have noted many times that sliders have dramatic platoon splits. They are fantastic against same-handed batters, but not so much against hitters that stand on the opposite side of the plate. So you hope to see a pitcher who relies on his slider also throw a third pitch, perhaps a changeup, to go to war against opposite-handed batters with.

Unfortunately, Ross doesn’t have one of those. Well, he does, but he threw his changeup just 7.1% of the time. And it was bad. Like, terrible. The pitch generated a SwStk% of just 4.6% (versus the 14.9% average) and it even generated grounders at a worse than league average mark. So he is essentially a two-pitch pitcher, fastball-slider. That’s not an automatic death sentence. If you sort the 2015 starting pitcher leaderboard by Slider%, you find all very good names at the top of the list. Look who’s number one, Joe’s very own older brother, Tyson.

Tyson throws his changeup even less than Joe did and is an absolute two-pitch pitcher. He obviously makes it work. Sure, lefties have given him more trouble than righties throughout his career (.320 wOBA against/3.84 xFIP vs .282 to righties/3.13 xFIP), but he’s still decent enough against lefties that his dominance of righties is enough to ensure he remains a very effective pitcher.

Joe, though, didn’t make it work. Lefties crushed him to the tune of a .351 wOBA and 4.99 xFIP, while his K/BB ratio shrunk from 7.0 against righties to just 1.8 against lefties. Even his ground ball rate was nearly cut in half against left-handed batters. If you had no idea you were looking at lefty/righty splits for the same pitcher, you would be fairly certain you were looking at the underlying skills of two different pitchers.

If you remember in my intro, I mentioned my article from a season ago about Carlos Martinez. In it, I expressed my serious concern about his inability to get lefties out. In 2014, he allowed a .363 wOBA to lefties (4.84 xFIP), versus just a .275 mark to righties (2.63 xFIP). Those splits are eerily similar to what Ross posted in 2015. But sure enough, as if on cue, Martinez doubled his changeup usage in 2015, while also upping both its SwStk% and ground ball rate. Suddenly his handedness splits looked more like Tyson Ross‘ and he enjoyed a breakout year with a 3.01 ERA/3.44 SIERA.

The difference here is that Martinez’s changeup actually started off good, as it sported a 17.5% SwStk% in 2014. Ross’ stinks, so it’s not just a matter of throwing it more against lefties and he’ll magically be more effective against them. He either needs to improve the pitch dramatically or figure out how to get lefties out with his sinker or slider. It’s a tall order.

—

Like Martinez, there is an assortment of both real positives and negatives when it comes to evaluating Joe Ross. I’m still willing to take the gamble, even in 12-team mixed leagues, if his price isn’t inflated by the sleeper hype. But just remember that there’s real risk here that isn’t so apparent when just looking at his overall seasonal skills.