Mike Moustakas has seemingly reinvented himself. We've been over this quite a bit. Here. There. Everywhere. He has started hitting the ball to the opposite field against the shift, which is great because he is still being shifted on a lot. He's passing the eye test, more or less. It certainly seems like he's trying to do less with outside pitches. He's just trying to slap things the other way. The easy hits. The cheap hits. Hits are hits, and getting on base is getting on base, however it happens. I'll take it.
Fangraphs released new batted ball data that goes back to 2002, so it's useful to look at ways in which "OppoMoose" is different and similar from "ShiftyMoose." Consider the following data points a more granular look at Moose's new batted ball tendencies and what's really driving his new identity. I'm not really going to prognosticate here - I'm not entirely sure yet how strong the relationship is between the new batted ball data and overall performance. It will be instructive to see the differences, though.
The first noticeable difference is that Moustakas is striking out a lot less. In fact, Moose is tied with Alcides Escobar for the seventh lowest strikeout rate among qualified hitters. Since he is not trying to pull the ball all the time, he's not trying to hit for power all the time, and presumably he's simply maturing. This makes sense.
The second noticeable difference is in Moose's batted ball frequencies. He's taken some of the fly balls he usually hits and instead turned them into ground balls and line drives. It's still early, so it remains to be seen if that will continue. It's possible that a flatter swing is partly responsible for this shift. This flatter swing, if it exists, would also go along well with the reduced strikeout rate. However, Moose is popping up more than ever. Fully 26% of his fly balls have been of the infield popup variety, which is a large increase from last season. OppoMoose is still PopupMoose.
The third noticeable difference is in Moose's spray angles. Part of the new Fangraphs stuff is pull, center, and opposite percentages on batted balls. These percentages are probably exactly what you think they are, both in definition and magnitude with regard to Moose. Moose has increased his opposite field percentage from 21% to 36%.
To give you some context about that change, I gathered all hitters who have had qualifying seasons in 2014 and 2015, which left me with 106 hitters (which did not include Moustakas). The average change in opposite field percentage was about 0%. The standard deviation was 5.3%. Out of that 106, only Xander Bogaerts has a larger increase in going to the opposite field than Moose. In other words, Moose has made a drastic change (a 3 standard deviation from the mean change) in a characteristic that would appear to stay relatively static. We knew Moose had been going to the opposite field more; Moose ranks fourth overall in opposite field rate. This gives you more context on just how much more.
That brings me to the fourth noticeable difference, which is in Moose's soft/medium/hard hit rates. According to the linked article above, these rates are currently calculated by using the batted ball type, hang time, and distance hit. Overall, Moose has decreased his hard hit rate, which means his soft hit and medium hit rates have gone up. Since Moose has been going to the opposite field more, and taking those cheap slap hits, this makes perfect sense.
That's not the end of the batted ball data, though. The pull/center/opposite and soft/medium/hard stuff can apply to each individual batted ball type. On grounders, Moose has not actually changed his ways that much - his pull percentage has decreased from 71% last year to 67% this year. His grounder opposite rate has gone up by only 2.5 percentage points. He is also hitting the grounders a lot weaker - his soft rate has increased from 20% to 36%. It's not through grounders that OppoMoose is making himself known. It's not through fly balls either. Moose has had an increase in opposite field rate on fly balls, but it's a modest increase.
The biggest change is in line drives. Last year, Moose took about 13% of his line drives to the opposite field. This is in line with previous years; Moose was who he was. This year, however, Moose has taken 61% of his line drives to the opposite field. I would try to give you context on that, but Fangraphs doesn't have the functionality that allows me to do so. I think you can guess who would lead this category.
At the same time, Moose is not hitting his line drives quite as hard. His hard hit rate on line drives has decreased from 59% last year to only 26% this year, the lowest of his career. The results have more or less followed what you would expect. Moose is hitting his line drives less hard, but he's hitting them where the fielders aren't. His on base percentage on line drives has increased from last year, but his slugging percentage has decreased. The result is basically MLB-average production on line drives.
Overall, Moose has undergone what is likely an unprecedented change in his batted ball abilities. These kinds of things don't normally happen. He is not hitting the ball quite as hard, but he's simply doing much better at hitting the ball where there isn't a fielder waiting to catch it. Pitchers will adjust and probably throw Moustakas differently. Maybe they'll throw him fewer strikes. Maybe they'll change their pitch location. It's possible that's already happened; last year, pitchers almost exclusively tried to throw Moustakas pitches low and away. This year, pitchers are kind of all over the place. Maybe teams will shift on him less or change the intensity of their shifts. At any rate, I'm glad that Moose has finally joined the cat-and-mouse game of adjustments. This has been a spectacular entrance into that game.