It’s April. That’s going to be said for the next few weeks, because April usually brings about the most small sample size hot takes. Even in May the sample size is of course bigger but still subject to needing more events. However there are things that stabilize more quickly than others. For instance swing%, contact%, and strikeout% all become reliable after about 100 plate appearances. That’s roughly early May for everyday players. Of course some things take a full year or more to really become reliable and there are different levels of reliability and prediction of true skill level/result. There’s a point of diminishing returns once you pass the reliability threshold.
One of the big narratives around Mike Moustakas in the last few years was how he was changing his approach to try to go opposite field, at least to beat the shift. He did just that in 2015 and 2016 (at least the part of 2016 he played in) with career-highs in percentage of balls hit the opposite way at 27% and 30% respectively. This led to career highs in wRC+ and the best season of his career in 2015 (3.6 fWAR). So now that Moustakas has come out of the gate in 2017 as hot as ever, you’d think this was just a continuation of what he was doing the past few years, right?
Remember I spoke about sample size and reliability just a second ago? Well opposite%, center%, and pull% (measurements of where a hitters batted balls are distributed) generally stabilize within 30-60 batted balls. Pull% specifically stabilizes around 30 balls in play. As of this writing, Moustakas is one batted ball shy of reaching 30. So how does his batted ball profile look?
There are huge changes so far this year for Moose. He is showing a large jump in fly-ball%, HR/FB%, and center%, with a big drop in opposite%. Moustakas has reverted (so far) back to his old ways of pulling the ball more, which has likely lead to the jump in center% too, where the ball will likely go if he can’t pull it. Again, I say “so far” because stabilization rates aren’t unanimous across the board (it’s really hard to figure out true talent levels in case you haven’t noticed by now) but maybe this could be the new-old Moose.
Let’s look at it this way and suggest that perhaps Moustakas has embraced the shift and just decided that he’s going to just hit the ball over their shifted heads instead. Over the past three years, Moustakas has a 63 wRC+ against the shift (.273/.271/.345), which is roughly the equivalent of Alcides Escobar at the plate. “Beating the shift” hasn’t really worked for him, otherwise teams would have stopped shifting him. So far this year of his 44 plate appearances, he’s been shifted in just over half (54%) and produced a 19 wRC+ (.208/.208/.250). When teams have shifted him so far this year he’s hit the ball into the shift half the time and to center the other half. The shift is working against him in some capacity. So it doesn’t seem like he’s trying to beat the shift necessarily.
So let me propose another thing and ask if perhaps Moustakas has joined the fly ball revolution?
He’s seen a noticeable jump in launch angle this year which of course coincides with his spike in HR/FB% (a percentage of how many fly balls go for home runs). Launch angle doesn’t stabilize as quick as batted ball data, it doesn’t take too long to stabilize (per FanGraphs).
There’s a big jump from ~30 to ~60 batted balls in stabilization rates for launch angle, so we aren’t there just yet where we can say that Moustakas is trying to hit the ball in the air more.
Also I know you may be thinking that a 31% HR/FB% can’t last, and while it is unlikely, it has happened several times before in a season. If pulling the ball is the best way to access power and you have to hit a fly ball to hit a home run, you’d expect some correlation between pull% and HR/FB%, right?
As you can see there is a decent correlation between the two, and a negative correlation (as one goes up the other goes down) between HR/FB% and cent%/oppo%.
We know of guys like Daniel Murphy, Josh Donaldson, and J.D. Martinez turning their careers around by hitting the ball in the air and while there are those that aren’t fully coming around to increasing launch angle, it’s gaining more traction.
He’s gone back to his older ways of pulling the ball and that’s lead to an early uptick in power (he has twice as many home runs as he did at this point last year). We aren’t quite ready to deem Moustakas as joining the fly ball revolution but here in the next few weeks we may or may not be able to.