To say that Mike Zunino's big league career with the Seattle Mariners has been a bumpy ride thus far is probably a bit of an understatement.
The catcher was taken with the third overall pick in the 2012 MLB Draft, and while college players sometimes get fast-tracked through the minors -- Zunino was selected out of the University of Florida -- it doesn't always bring the best possible results. It took him just 96 minor league games (and 419 plate appearances) to reach the majors in 2013, and it was easy to look at his Isolated Power (ISO) of .160 through 1,055 plate appearances (supported by launching 38 homers) and think awesome things are coming.
That is, until you take a peek at the rest of his stats, which included a .193/.252/.353 triple slash with a 71 wRC+ and .268 wOBA.
It appears he was rushed, which is why he finished the 2015 season and began 2016 in Triple-A. Upon getting recalled to the big leagues, he showed some progress in his development by posting a 115 wRC+ and .338 wOBA with 12 homers in 192 plate appearances.
And so far this year? He's taking another step forward by hitting .257/.321/.500 with 9 homers and 30 RBI in 168 plate appearances. That's led to a 120 wRC+ and .346 wOBA, both of which are on track to be single-season career highs.
Zunino can thank his current hot streak during the month of June for these solid overall numbers. It seems like it came out of nowhere, but we should've been anticipating one.
A Gradual Shift ... In Some Places
As with most hot streaks on the diamond, we can see the cause in a player's peripheral stats. The first two months of Zunino's season didn't bring a whole lot of success, but he progressively improved his batted-ball profile before taking things to another level in June.
The below table shows how Zunino's line-drive rate (LD%), ground-ball rate (GB%), and fly-ball rate (FB%) have changed each month this season.
| Month | PA | LD% | GB% | FB% |
|---|---|---|---|---|
| April | 70 | 15.4% | 38.5% | 46.2% |
| May | 40 | 37.5% | 31.3% | 31.3% |
| June | 58 | 33.3% | 24.2% | 42.4% |
The sample sizes vary a bit, but they're similar enough for us to see that he made some significant changes. Obviously, his line-drive rate experienced a huge spike while the fly-ball rate did some yo-yoing, but most importantly, his ground-ball rate has consistently gone down in each month.
It shouldn't be totally surprising that he's experiencing such incredible success right now -- after all, it's hard for a hitter with power to not have success with a batted-ball profile that looks like his does this month.
It'll be even less surprising upon seeing how his quality of contact has changed during the same period.
Great Process, Overdue Results
In his short stint with the big club last season, Zunino posted a career-high 35.0% hard-hit rate, and he's taken yet another step forward in that department this year with his current 42.0% mark.
Similar to his batted-ball profile, he's gradually increased his hard contact, and he has done so at the expense of his soft-hit rate. The below table shows how his soft-hit rate (Soft%), medium-hit rate (Med%), and hard-hit rate (Hard%) have changed each month. To show the difference in his results, his wOBA and wRC+ from each month are also included.
| Month | PA | Soft% | Med% | Hard% | wOBA | wRC+ |
|---|---|---|---|---|---|---|
| April | 70 | 20.5% | 43.6% | 35.9% | .218 | 33 |
| May | 40 | 6.3% | 50.0% | 43.8% | .308 | 94 |
| June | 58 | 6.1% | 45.5% | 48.5% | .528 | 244 |
For further context, that ridiculous wOBA and wRC+ he's produced so far in June both currently lead the league. For someone that's been hitting the ball this hard and combining it with what we outlined in the previous section, it was only a matter of time before things started going his way.
They always used to tell us in Little League that if you hit the ball hard as often as possible, good things will eventually happen. Guess they weren't lying.
It's not as if there still aren't some things to be concerned about with Zunino -- his plate-discipline numbers don't look terrible (outside of his 16.5% swinging-strike rate), but his 38.7% strikeout rate would rank second behind only Keon Broxton if he qualified for the batting title.
He's never been known to make a ton of contact, and his current 66.2% contact rate this year is well below the league average. So, it's important for him to make the most of the pitches he does connect with. He's been doing a good job of that so far this year for the Mariners.