It’s almost as if over the 4th of July holiday in 2015 (actually slightly later) in the spirit of the USA, a couple of B-52 planes dropped large payloads of “juiced” balls over every MLB stadium. This recent rise in what some are calling a “juiced” ball may be leading to the surge in home runs we’ve seen roughly the past two years.
Now I put juiced in quotes on purpose. It’s not that I don’t think the ball isn’t different, it’s just that juiced carries a negative connotation (as in purposefully being deceitful). Long story short, the current baseballs are at a higher COR (coefficient of restitution) than in the past, thus making them more bouncy you could say. This higher COR wasn’t a product of the MLB saying “let’s juice the balls”, but instead the COR of balls is reaching the upper boundaries of the tolerance that MLB set for their balls COR to have. So they aren’t cheating necessarily, but perhaps they didn’t calibrate their COR range correctly, allowing for a tolerance level that would impact the game more than they thought. It’s possible that the MLB said “let’s push the balls to their upper acceptable tolerance” but they’ve come out and said they didn’t do that. Would that be cheating or wrong of the MLB to do? We know they are looking to boost offense with the rise of pitching velocity, and they could have told Rawlings to boost the COR pretty easily.
Though it’s not a theory I’m sure I believe, some people think there was a change in a supplier of materials for Rawlings that set things off. It’s also worth noting that the MiLB and MLB use different balls made from different factories, and as far as we can tell, the minor leagues have seen no significant increase in home runs on the level that the MLB has seen.
The players that have seen the biggest gain from the new ball are those in the middle class of power, those who a small change in batted ball distance would help them the most. Giancarlo Stanton and Aaron Judge don’t need an extra 5-7 feet on their batted balls; they are leaving the park regardless. Meanwhile guys like Ben Revere aren’t suddenly going to be sluggers either because they simply don’t hit it hard or far enough. Who instead it helps are those moderate power guys. I think there is one guy on the Royals team that perhaps screams moderate power: Whit Merrifield.
Perhaps not a coincidence that timing with the surge of moderate power guys has also been the moderate power that Whit Merrifield has shown over the past 500-600 plate appearances.
Merrifield never hit more than eight home runs (nine combined) at any level in the minors, yet this year in the majors he’s approaching doubling that mark, as well as having an isolated slugging 80 points higher than in 2016.
So what’s changed?
Merrifield has increased his launch angle ~5 degrees this year, among the top 30 or so biggest increases since last year:
That group last year averaged a .161 ISO (Merrifield well below that at .109), and now they are average a .189 ISO (Merrifield right on that). On average though, they experienced around a 30 point increase in their ISO, Merrifield has seen an 80 point spike, third only to Logan Morrison and Scott Schebler.
Among leaders in ISO changes since last year, Merrifield finds himself easily inside the top 20:
There is something weird about that list too. Schebler and Merrifield stand out pretty well (more so than Jose Ramirez or Brett Gardner) compared to everyone else there. Stanton, Springer, Goldschmidt, etc... are premier power hitting guys, while the others are at least above average raw power. Then there is Gardner and Ramirez. Gardner plays at Yankee Stadium, so a power boost isn’t out of the question and he’s also pulling the ball and hitting it harder. Ramirez has been underrated his entire career (he’s been young and hit at every level and no one has batted an eye), and he’s 24 so a true power breakout isn’t implausible for a guy who was worth almost five wins last year.
Schebler isn’t an excellent hitter, but he’s an obviously strong guy who has hit 20+ home runs at three different levels (including the majors this year) while posting .230+ ISO’s almost every year. While he did have a big ISO change year-over-year since 2016, in 2015 he had a .250 ISO, so .245 is actually a small decline of an already raw power hitter who gets into it in games.
So if we instead forget about 2016 in light of Schebler and focus on a player's career leading up to 2017, we can see those players hitting above their career ISO:
There’s another list where Merrifield finds himself among the top 20 or so guys. The thing that really sticks out to me though is that at least leading up 2017, many of those guys were average or better power hitters (average ISO is ~.140-150). Altuve and Merrifield are the two that stand out and Altuve is 1) a freak of a hitter 2) had almost a 20 point lead on Merrifield and 3) his ISO has been making 20-30 point increases every single year.
Merrifield is by far and away hitting for more power than his career ISO peer group:
It’s worth wondering if those guys have made similar launch angle changes as Whit.
That’s a bit inconsistent across the board. Second to Whit in ISO change is Hernan Perez, and he’s actually decreased his launch angle this year a bit. Meanwhile Ben Gamel has gone through a larger launch angle change than Merrifield, but hasn’t seen nearly the spike Merrifield has. It’s worth noting that Merrifield in that group has both the largest ISO change and highest average launch angle.
I just don’t buy that an increase in launch angle alone has turned Merrifield into a .190 ISO hitter. An increased launch angle certainly could help, but just lifting the ball more probably wouldn’t almost double your career ISO unless you are hitting the ball harder too.
A ball hit at 87 MPH and 10 degree launch angle is a home run 0% of the time (based on prior data). A ball hit at 87 MPH and 15 degree launch angle is still a home run 0% of the time. Even 87 MPH at 20 degrees isn’t a home run either. You’ve really gotta start getting into 95+ MPH batted balls to start making home runs.
Merrifield’s average exit velocity:
2016: 87 MPH
2017: 87.2 MPH
Merrifield’s average batted ball distance:
2016: 167 feet
2017: 206 feet
Merrifield has picked up 40 feet of batted ball distance without hitting the ball any harder.
Again you see Whit amongst names that he doesn’t really belong in (Trout, Carter, Davis, Martinez, Moustakas, etc...). These are players who have hit the ball as far on average as him, but they on average have almost one degree higher launch angle and two miles per hour more exit velocity. Merrifield is at the bottom of the list in exit velocity here, and behind most on average launch angle too. When you take career through 2016 ISO into consideration too, it’s even more strange:
These guys on average had almost double Merrifield’s career ISO, but now Whit is hitting the ball as far as them but not as hard or for as much power.
Whit has been increasing his launch angle steadily over the season, but it might not be having the desired effect he’s looking for:
One of his best power months came with his lowest launch angle, while his highest launch angle so far hasn’t lived up to the power in the prior month (small sample size warning for August).
I can buy that a swing change can help Merrifield some (and before anyone brings up his offseason regimen - he tried it last year too), and he’s definitely hitting more fly balls (as evidence of the swing change), but seeing him be the outlier on all these lists of power hitters (1B, DH, and corner outfield types) raises my eyebrows a bit. To me, he seems to be among the leader in guys benefitting from the “juiced” ball. That’s not a bad thing, Merrifield can’t help what ball the MLB uses, but it’s certainly helping explain his career year he’s likely posting right now. In the land though where everyone is seemingly setting career highs in power due to a “juiced” ball, Merrifield may be king.