STRO STICKS WITH PITCH
Slumping Jay likes sinker
Back in early May, when Marcus Stroman was still the shock-topped phenom and not a starting pitcher mired in the worst slump of his short major-league career, he spoke about his sinking fastball, the key pitch in his arsenal.
It induces a lot of ground balls, some of which can become singles through the infield, he told a Toronto reporter. “But it’s a pitch that I live and die by,” he said, “so it’s something I’m going to continue to throw and not shy away from at all.”
Reading that comment now, there is a tinge of something ominous about it. Especially the dying part.
Stroman, the 25-year-old who had shown enough in parts of two seasons in the majors that he was the obvious candidate to become the Blue Jays’ staff ace, has instead regressed mightily: a 5.33 ERA through three months, after a sparkling 1.67 ERA in his return from knee surgery last September, and before that a solid 3.38 ERA in the second half of 2014.
The stupidest explanation for the change in his effectiveness, mostly limited to callers to radio shows, is that Stroman has too much swagger. No, he was cocky two years ago and brimming with confidence even coming back from injury last year. Stroman has always pitched with a Sisyphean boulder on his shoulder, owing to the doubts about his small size, and it has served him well.
What seems to be serving him far less well is that sinker. Over the past two seasons, Stroman has transitioned from a pitcher who threw a lot of four-seam fastballs — a basic fastball — to one who relies heavily on the twoseam sinking fastball. He threw the four-seamer 44 per cent of the time in 2014, according to Fangraphs, and this season is throwing the two-seamer 49 per cent of the time. He has used the rest of his arsenal — slider, cutter, curve, change-up — at relatively unchanged rates.
An effective sinker means a pile of ground balls, and there is no doubt that switching to it has had that desired effect for Stroman: his ground ball rate of 58.8 per cent is now highest among American League starting pitchers, and his fly-ball rate is second-lowest. His ground-ball to fly-ball ratio is second-best in the AL, behind only his pal Aaron Sanchez. But he’s also striking out fewer batters and walking more of them, which isn’t totally surprising because the old four-seamer is an easier pitch to control.
The biggest problem, though, is that batters are hitting that sinker a lot. Opponents are hitting .308 off the sinker in 2016, after just .214 off it in the small sample of last fall. Some of that can be attributed to luck — batters have an unusually high .318 average off sinkers put in play in 2016 after just .236 in 2016 — but overall the percentage of balls hit hard off Stroman, per Fangraphs, has jumped significantly: 33.6 per cent this year from 21.8 per cent last year.
The difference in effectiveness between the old fastball and the new one is stark. In 2014, Stroman’s fastball value — the number of runs saved using it — was 12.8, which was sixth-best in the AL among starters, just behind Chris Sale. This season, it is -2.1, or below league average. His cutter and change-up are also below average, while the slider and curve are about at the AL standard. This is not a recipe for domination.
Consider that Marco Estrada, also not a pitcher with dominating power, throws a fastball this season with a value of 12.8 — second in the AL — and a change-up of 7.6, good for third in the league. His fastball is of the trusty fourseam variety. J.A. Happ has a very effective fastball and equally strong curve, while Sanchez is getting above-average results on three of his pitches.
So, why are Stroman’s pitches all so suddenly ineffective? Dirk Hayhurst, the former Blue Jay turned analyst, wrote at length for TSN this week that the old fastball set up the rest of Stroman’s pitches better than does the sinker.
Certainly, it looks like reliance on the sinking fastball has taken some of the mystery out of at-bats for hitters. Stroman in 2016 is throwing 66 per cent of his pitches in the lowest two-fifths of the hitting zone, where in 2014 he kept the ball that low 53 per cent of the time, according to zone profile data from BrooksBaseball.net.
Meanwhile, while batters are hitting just .100 on sinkers down and in to right-handers, they are thumping it almost everywhere else: the batting average off Stroman sinkers in the strike zone is .338 in 2016. Basically, if they avoid the sinker in that one location, it has been alarmingly hittable.
Some of this, to be sure, is poor luck. The .322 average on balls in play off Stroman is abnormally high this year, so over time he should see some positive numbers there.
But something from Stroman needs to change, too. More variety of pitches, better sequencing, more effective use of the other edges of the strike zone, including up, something to make him a little less predictable. Stroman this year is giving the low part of the strike zone a pounding. But the hitters are returning the favour.