Eric Hosmer's story is well known. General Manager Dayton Moore's first round pick in 2008, Hosmer reached Kansas City in 2011, where he had a fantastic rookie season and looked to be the star everyone thought he could be. Unfortunately, Hosmer's career has been up and down. Hosmer turned in an extraordinarily poor 2012 before a bounceback 2013. Most saw 2012 as a simple sophomore slump, but, again, 2014 proved thoroughly mediocre.
Fortunately, Hosmer is having a breakout season this year by all accounts. Hosmer is hitting a beautiful .310/.373/.464, walking almost 9% of the time. This adds up to a 130 wRC+; in other words, Hosmer is hitting 30% above league average, which is a career best. He is almost certain to best his 2013 total in Wins Above Replacement with about a month to go.
Still, Hosmer has immense potential, and he isn't quite reaching it. His average and plate discipline are both very good, but his one deficiency this year has been something that you wouldn't really consider: power.
Yes, Hosmer hasn't displayed much power this year.
At first glance, that statement doesn't make sense, because he has done this
all of which are from this year. Most impressive about Hosmer's home runs are the length and location. All four of those are to different fields--left, right, left-center, and right-center. And, according to ESPN's Home Run Tracker, Hosmer's average home run length is 420 feet, or second-highest among all batters with at least 10 HR.
But numbers don't lie. The best single stat to determine power is ISO, or Isolated Power. It's a simple stat that just subtracts batting average from slugging percentage; players with a higher ISO hit for more power more often than those with a lower ISO. Here is the full list of Royals regulars or semi-regulars with an ISO higher than Hosmer:
- Paulo Orlando, .193
- Kendrys Morales, .183
- Lorenzo Cain, .179
- Ben Zobrist, .178
- Alex Gordon, .177
- Salvador Perez, .171
- Mike Moustakas, .170
Hosmer's ISO is a mere .154. Among qualified American Leaguers, that ranks 46th out of 76, which is closer to Erick Aybar and Alcides Escobar than Mark Teixeria and Chris Davis. Obviously, Hosmer can hit balls very, very far. So what on earth is going on?
First, let's take a look at the rate at which Hosmer hits balls hard. We can see this by looking at what Fangraphs calls 'Quality of Contact Stats.' They explain it here:
Soft%, Med%, and Hard% are based on data from Baseball Info Solutions (BIS) which attempt to capture how well each baseball was hit...Quality of contact doesn’t perfectly correlate with success on the field, but in general, hitting the ball hard or allowing weak contact is better than the alternative.
For the early years of quality of contact stats, the BIS video scouts had to make judgments, but since 2010, the video scouts recorded the amount of time the ball was in the air, the landing spot, and the type of batted ball (fly ball, ground ball, liner, etc) and the BIS algorithm determines if the ball was soft, medium, or hard hit.
A hard hit ball can be a grounder, line drive, or fly ball; these stats measure how hard the ball is hit regardless of type. Here is Hosmer's placement among all 76 qualified hitters as well as the nearest four players above and below him:
|Kendrys Morales||Royals||14.4 %||51.9 %||33.7 %||0.292||0.356||0.476||128||0.321|
|Kyle Seager"]">Kyle Seager||Mariners"]">Mariners||12.1 %||54.5 %||33.5 %||0.270||0.329||0.455||118||0.282|
|Robinson Cano"]">Robinson Cano||Mariners||15.5 %||51.0 %||33.5 %||0.278||0.325||0.422||108||0.313|
|Albert Pujols"]">Albert Pujols||Angels"]">Angels||15.5 %||51.1 %||33.3 %||0.246||0.311||0.489||121||0.218|
|Eric Hosmer||Royals||18.6 %||48.2 %||33.2 %||0.310||0.373||0.464||130||0.354|
|Prince Fielder"]">Prince Fielder||Rangers"]">Rangers||15.8 %||51.2 %||33.0 %||0.312||0.380||0.467||126||0.325|
|Shin-Soo Choo||Rangers||14.4 %||53.0 %||32.6 %||0.253||0.349||0.432||112||0.312|
|Nick Castellanos"]">Nick Castellanos||Tigers"]">Tigers||12.0 %||55.4 %||32.6 %||0.249||0.304||0.420||96||0.307|
|Brian McCann||Yankees"]">Yankees||14.1 %||53.5 %||32.4 %||0.245||0.329||0.483||121||0.244|
Hosmer is near the top, ranking 21st. As you can see, the hitters around Hosmer are all above average except for Nick Castellanos. Hosmer is the most productive out of all of them, but that's partially due to good luck and success at putting balls in play.
So we've established that Hosmer hits the ball hard and that he has the ability to hit to all fields. Why, then, is his power so low?
The answer is simple: Hosmer hits too many ground balls.
It is impossible to hit home runs with ground balls*. The only balls that have any chance of going for a home run are those that are hit in the air. Furthermore, while it is possible to hit a hard grounder into the corners for extra bases, most ground balls do not go for extra bases unless the defense is involved in an extreme shift or extreme stupidity.
Ground balls do indeed go for hits more often-especially fast runners, like Jarrod Dyson, can regularly gather infield hits or bunt for hits on grounders, and slower runners can still put balls through the holes in the defense for singles (see Billy Butler's entire career).
But unless you hit for a high average and get on base a ton through walks, AKA the Joe Mauer approach to offense, hitting for power is the easiest way to increase your total offensive output.
The following is a table of the top ten ground ball hitters out of the 76 American League qualified hitters.:
|Jose Iglesias"]">Jose Iglesias||Tigers||21.0 %||55.9 %||23.2 %||0.300||0.347||0.370||98||0.330|
|Joe Mauer||Twins"]">Twins||23.0 %||55.4 %||21.5 %||0.267||0.334||0.376||92||0.313|
|Anthony Gose"]">Anthony Gose||Tigers||20.7 %||53.7 %||25.6 %||0.254||0.313||0.372||88||0.343|
|Xander Bogaerts||Red Sox"]">Red Sox||20.6 %||52.9 %||26.5 %||0.320||0.349||0.414||107||0.368|
|Erick Aybar||Angels||20.2 %||52.9 %||26.9 %||0.269||0.303||0.324||77||0.300|
|Billy Butler||Athletics"]">Athletics||16.7 %||52.6 %||30.7 %||0.249||0.321||0.378||96||0.285|
|Eric Hosmer||Royals||24.4 %||51.6 %||24.0 %||0.310||0.373||0.464||130||0.354|
|Austin Jackson"]">Austin Jackson||Mariners||23.3 %||51.1 %||25.6 %||0.272||0.312||0.387||97||0.348|
|Robinson Cano||Mariners||24.6 %||50.8 %||24.6 %||0.278||0.325||0.422||108||0.313|
|Shin-Soo Choo||Rangers||20.8 %||50.8 %||28.4 %||0.253||0.349||0.432||112||0.312|
Yes, that is our very own Eric Hosmer hanging out at seventh place, hitting grounders 51.6% of the time. Notice how hitting lots of ground balls correlates negatively with overall offensive production--Hosmer is the only truly effective hitter out of this bunch. Hosmer hits a fly ball only 24% of the time, which means that he can only get a home run once out of every four balls he puts in play at the maximum.
From the other direction, we can see that fly balls are very helpful to overall offensive production:
|Jose Bautista"]">Jose Bautista||Blue Jays"]">Blue Jays||0.249||0.369||0.533||145||14.5 %||37.1 %||48.4 %||0.233|
|Brian McCann||Yankees||0.245||0.329||0.483||121||17.4 %||34.8 %||47.7 %||0.244|
|Luis Valbuena"]">Luis Valbuena||Astros"]">Astros||0.209||0.295||0.413||95||19.5 %||34.0 %||46.5 %||0.217|
|Brian Dozier||Twins||0.242||0.312||0.474||113||23.4 %||32.4 %||44.1 %||0.266|
|Chris Davis||Orioles"]">Orioles||0.256||0.342||0.548||140||24.7 %||31.5 %||43.8 %||0.311|
|J.D. Martinez"]">J.D. Martinez||Tigers||0.285||0.347||0.553||144||21.8 %||34.5 %||43.8 %||0.339|
|Edwin Encarnacion"]">Edwin Encarnacion||Blue Jays||0.268||0.361||0.535||142||20.4 %||36.0 %||43.5 %||0.263|
|Mookie Betts||Red Sox||0.282||0.328||0.463||111||18.6 %||38.1 %||43.4 %||0.298|
|Carlos Beltran||Yankees||0.276||0.338||0.474||121||21.0 %||36.5 %||42.6 %||0.307|
|Asdrubal Cabrera"]">Asdrubal Cabrera||Rays"]">Rays||0.263||0.318||0.422||105||21.5 %||36.3 %||42.3 %||0.314|
Rather than the likes of Aybar, Gose, Butler, and Jackson we see Bautista, Davis, Martinez, and Encarnacion.
And, to be complete, line drives are also very good as well:
|Jason Kipnis"]">Jason Kipnis||Indians"]">Indians||0.311||0.385||0.458||134||28.1 %||45.2 %||26.8 %||0.365|
|Chase Headley||Yankees||0.274||0.340||0.396||104||27.0 %||43.3 %||29.7 %||0.331|
|Ian Kinsler"]">Ian Kinsler||Tigers||0.305||0.356||0.449||122||25.3 %||34.1 %||40.6 %||0.333|
|Brock Holt||Red Sox||0.282||0.353||0.384||102||25.2 %||50.3 %||24.5 %||0.353|
|Mike Trout"]">Mike Trout||Angels||0.298||0.397||0.581||170||24.8 %||37.5 %||37.7 %||0.343|
|Chris Davis||Orioles||0.256||0.342||0.548||140||24.7 %||31.5 %||43.8 %||0.311|
|Miguel Cabrera"]">Miguel Cabrera||Tigers||0.353||0.452||0.572||179||24.7 %||41.8 %||33.6 %||0.400|
|Robinson Cano||Mariners||0.278||0.325||0.422||108||24.6 %||50.8 %||24.6 %||0.313|
|Eric Hosmer||Royals||0.310||0.373||0.464||130||24.4 %||51.6 %||24.0 %||0.354|
This table combined with the Quality of Contact table helps paint why Hosmer is a good hitter: he hits lots of line drives and he hits balls hard.
But this table also shows the true limit to Hosmer's approach. Hosmer is basically the equal to every hitter on the table except for Trout, Davis, and Cabrera. But all three hit significantly more fly balls and therefore get significantly more home runs.
Hosmer's breakout season has been fantastic, but his offensive value will plateau unless he converts more of his grounders into fly balls. Again, we know that he has the ability to hit home runs out of Kauffman Stadium routinely. Here's another example for kicks-Home Run Tracker has it at 452 feet, which is out in every part of every ballpark in the Majors:
Though it's easier said than done, Hosmer has the pure ability to be one of the best hitters in baseball. Whether or not he makes the adjustment to be so is anybody's guess.