Heading into the 2016 season, it was all but acknowledged that Marcus Stroman would assume the role as the team's ace, getting called upon every five days with the expectation, not hope, of a victory. Instead, Aaron Sanchez was unleashed onto the baseball world, quickly becoming one of the most dominant pitchers in the American League.
However, nearly anytime you have a conversation about how good Sanchez is, a much more disheartening thought accompanies it. That is, when will Sanchez have to be either shutdown or relegated back to the bullpen to manage his innings increase from previous seasons. This is a can of worms that has been stewing opened for some time now.
The first notable instance of this discussion was in 2012 when the Washington Nationals placed Stephen Strasburg under a hard innings limit of 160 innings, shutting him down at 159.1 in early September. He didn't play in the playoffs where his team was promptly defeated by the St. Louis Cardinals. It became ever more apparent with the New York Mets last season when the innings limit became a near soap opera with Matt Harvey, agent Scott Boras and of course the Mets organization. From the outset Harvey was supposed to be under a 180 inning cap and scheduled to be shut down to save some innings for the postseason. Instead he pitched 189.1 innings in the regular season before pitching another 14 innings in the postseason. While some may point to his poor start to the 2016 season as a sign of his overwork, it can't be ignored that the extra weight he's put on has played a factor to his overall lack of success as well.
Whenever you see these types of inning limits put invoked, you have to ask yourself why they're doing it and what exactly it means. Many times when you're watching the game, you'll hear this ominous yet ever-present talk about removing the starter from the game at "100 pitches." Following the same line of thinking is the mantra that you should limit a starter's innings increase to a prescribed percentage so as not to overload the pitcher and create injury. This cookie-cutter method is completely illogical and, moreover, not backed by actual quantitative analysis and science.
Instead, take for example a University of Waterloo study published in last year's April Journal of Sports Medicine and Physical Fitness that found no correlation between innings pitched and future injury, nor the number of pitches thrown to injury. The study looked at every Major League pitcher under 25 who made at least one start between 2002 and 2007, proving that the practice of limiting the increase of innings pitched per year was not statistically significant in predicting whether or not an injury would occur to a pitcher.
Thomas Karkolis, the lead investigator for the study, did tell the Toronto Star's Brendan Kennedy that reducing the workload was definitely necessary however, there is more to it than a number of pitches or innings.
"By just putting blanket innings limits on pitchers or pitch counts, that's not going to get you the results you're looking for in terms of reducing the number of injuries," he said to Kennedy.
To anyone who's even tried throwing a curveball, slider or even knuckleball, that's undeniably true. All pitches are not created equal. While throwing a fastball may seem like a free and easy motion, the strain put on your elbow throwing a curveball or slider is much different. Thus, all 100 pitch outings aren't the same. Sometimes you're required to throw 80 per cent fastballs and others you have to rely on pitches which may be more physically demanding.
Let's not forget another variable in a pitcher's endurance: inning length or leverage. If a pitcher is required to throw more pitches in an inning without adequate rest in between pitches, it stands to reason the incidence for injury would likely be increased. Same goes for the scenario when constantly pitching in high-leverage situations which may require a pitcher to throw with everything he has more often than a pitcher who's 'cruising' through a game.
The question is where this gets us with Aaron Sanchez. In terms of leverage, Sanchez commands a 0.88 gmLl which is only slightly above the league average of 0.87 for starters. What this means is that Sanchez doesn't pitch in much higher leverage situations than essentially the league average. Conversely, when it comes to the amount of pitches Sanchez throws per inning, he ranks 45 of 51 qualified starters with 14.9 pitches per inning. What that tells you is that, thus far, Sanchez has not at all been stressed in terms of workload or pressure when pitching in games.
Of course, the most important point to be made about studying a pitcher's ability to handle an increased workload is his biometrics. In this, we're talking about a fancy word that basically measures how efficient Sanchez's body works during his delivery (his mechanics) to reduce the amount of strain put on his elbow, shoulder and essentially, body. To this, the Jays proprietary data would be better suited to testify to Sanchez's endurance level. Scouts and very similar technology to the type of vest that Stroman wore last season might be able to determine how tired Sanchez's body is when pitching and predict the likelihood of him getting injured if he continues working beyond his previous inning counts. In this, it seems anyways, that GM Ross Atkins understands this.
"I think percentage workload increases and thresholds are something that, it's really arbitrary," he told Jamie Campbell of Sportsnet last week. "There's not a lot of research or evidence to suggest you should stop at a certain threshold..."
Instead, he talks about the idea of incorporating a variety of opinions, including Aaron's, to determine when or if he needs to be shut down. "...the most important piece of that equation will be how he's feeling and not just subjectively but how things are viewed objectively."
Although it was reported initially during spring training that Sanchez would return to the bullpen at the end of the year, he doesn't necessarily have to. Even if he does, that decision is a long way off from today and needs to incorporate much more than an innings pitched metric.
Atkins said he believes that it's possible Sanchez is in the rotation at the end of the year. I'm certain if you asked Sanchez himself, he'd scoff at the imagined possibility of doing anything but starting. Give it a little time and maybe you will too.
Aaron Sanchez is the Jays best starting pitcher and he could be for the whole season. Get behind that.