Metrics 101: MLB's Most Overhyped Early-Season Breakout Stars

Zachary D. Rymer@zachrymerMLB Lead WriterApril 20, 2018

Metrics 101: MLB's Most Overhyped Early-Season Breakout Stars

0 of 10

    Let's pump the brakes on the Didi Gregorius hype train.
    Let's pump the brakes on the Didi Gregorius hype train.Billie Weiss/Boston Red Sox/Getty Images

    It's hard to know which breakouts to trust when Major League Baseball is still in the small-sample-size portion of a brand new season. Some are for real. Some lean more toward fraudulent.

    Today, MLB Metrics 101 is going to weed out the frauds.

    Hello and welcome back. Our goal is to address 10 breakouts from early in the 2018 season that are not what they seem. This involves using assorted metrics to highlight large discrepancies between what a player's results are and what his results should be.

    We'll start with five pitchers and end with five hitters.

    Note: The advanced metrics within are current through play on Wednesday, April 18.

Jarlin Garcia, Miami Marlins

1 of 10

    Julie Jacobson/Associated Press

    In 2017: 68 G, 53.1 IP, 4.73 ERA

    In 2018: 4 G, 21 IP, 0.86 ERA

    After serving as an anonymous lefty specialist in 2017, Jarlin Garcia has emerged as the biggest bright spot on the 2018 Miami Marlins.

    He did good work in relief in his first two outings of 2018 and has pitched like an ace in two starts since. He no-hit the New York Mets through six innings on April 11 and then one-hit the New York Yankees through five innings on April 17.

    If you squint, you can see the potential. Garcia works in the low 90s with his fastball and heavily features both a slider and changeup. He's also collecting plenty of ground balls.

    And yet, his margin for error will be slim as long as he walks (14.3 BB%) and strikes out (16.9 K%) batters at nearly the same rate

    Garcia also hasn't stifled exit velocity, as his average is at 88.6 mph, a figure that balloons to 95.5 mph when the sample is restricted to fly balls and line drives. On those, he's allowed just a .524 slugging percentage. By all rights, it should be more like a 1.224 slugging percentage.

    In short, "Jarlin the Marlin" has been a little too good.

Reynaldo Lopez, Chicago White Sox

2 of 10

    Nam Y. Huh/Associated Press

    In 2017: 8 G, 47.2 IP, 4.72 ERA

    In 2018: 3 G, 19.0 IP, 1.42 ERA

    For the most part, Reynaldo Lopez is showing why he was once considered one of baseball's top pitching prospects.

    The Chicago White Sox youngster is featuring a 95.5 mph fastball and snapping off sharp sliders and fading changeups. Opposing batters have had a tough time making contact against this stuff, as he's out there rocking a 28.4 K%.

    It's not as easy to be enthused about the walks, however. Lopez has issued free passes to 14.9 percent of the batters he's faced. That's a good way to put traffic on the bases, which is the easiest way to ask for trouble.

    And while contact off Lopez has been sparse, it's been loud. Air balls (i.e., fly balls and line drives) off him have traveled at an average of 94.6 mph. And since only a third of batted balls off him have been on the ground, he's been allowing a lot more fly balls than a guy like Garcia.

    That Lopez has surrendered only five extra-base hits is worth some suspicion. To wit, his expected slugging percentage on fly balls (1.210) is about the same as teammate Miguel Gonzalez (1.213), who's already given up 13 extra-base hits.

Homer Bailey, Cincinnati Reds

3 of 10

    Gary Landers/Associated Press

    In 2017: 18 G, 91.0 IP, 6.43 ERA

    In 2018: 4 G, 23.2 IP, 3.42 ERA

    Homer Bailey is...back?

    It may look that way, but he wouldn't be here if that were truly the case.

    When the Cincinnati Reds veteran was at his best back in 2012 and 2013, he combined a low walk rate with a high strikeout rate, the latter of which was the byproduct of a blazing fastball and other nasty pitches.

    This isn't what's happening with Bailey in 2018. His walk rate (8.3 BB%) is fine but comes paired with a modest strikeout rate (16.5 K%) and a fastball that's averaging just 91.9 mph. It may be a stretch to call him a "finesse" pitcher, but he's definitely not the power pitcher he used to be.

    Between this and the fact that his ground-ball rate is below the MLB average, it should surprise nobody that Bailey is flying the same red flag as Lopez. He's given up a lot of air balls, which have been hit hard at an average of 96.6 mph. 

    Per the National League-high gap between Bailey's expected slugging percentage (1.269) and actual slugging percentage (.559) on air balls, it's just a matter of time before his luck runs out.

Francisco Liriano, Detroit Tigers

4 of 10

    Duane Burleson/Getty Images

    In 2017: 38 G, 97.0 IP, 5.66 ERA

    In 2018: 3 G, 17.2 IP, 2.55 ERA

    Everything that was just said about Bailey's supposed comeback also applies to Francisco Liriano's supposed comeback.

    He has a higher strikeout rate, but otherwise the two veterans have the same baseline issues. Like Bailey, Liriano has also been ducking damage on well-hit fly balls and line drives. The 718-point gap between his expected slugging percentage (1.398) and actual slugging percentage (.680) on those is easily the highest in the American League.

    So, moving right along...

Mike Leake, Seattle Mariners

5 of 10

    Ted S. Warren/Associated Press

    In 2017: 31 G, 186.0 IP, 3.92 ERA

    In 2018: 4 G, 24.0 IP, 4.50 ERA

    Don't read too much into Mike Leake's 4.50 ERA. It was 3.50 going into the Seattle Mariners' tilt against the Houston Astros on April 18, in which he was excellent for six innings before crumbling in the seventh.

    Plus, he's an excuse to introduce a little variety into these proceedings.

    Leake's typical formula for success doesn't involve many strikeouts, but he's usually a reliable BB% maestro and further limits damage by keeping ground balls coming.

    But so far in 2018, batters are showing that they're on to Leake's act. They're not falling for his apparent strategy of throwing fewer actual strikes, and he's on track to finally fall victim to the launch-angle craze.

    Plus, the ground balls Leake is collecting should be doing more damage. They're being hit at a career high 88.7 mph. He's gotten ground-ball outs anyway, but the expected batting average on those is an MLB-high .290.

    On second thought, do read into Leake's ERA. It portends more or less the appropriate amount of doom.

Greg Garcia, St. Louis Cardinals

6 of 10

    Aaron Doster/Associated Press

    In 2017: 133 G, 290 PA, .697 OPS, 2 HR

    In 2018: 13 G, 28 PA, .995 OPS, 2 HR

    Greg Garcia is a late arrival to the early breakout club. He didn't see his first real action until April 10, and he's done all his damage since then.

    His pinnacle was a contest against the Cincinnati Reds on April 14 in which he went 3-for-4 with two home runs. In so doing, he matched his homer total from the entire 2017 season.

    "I don't hit many home runs, period," Garcia told reporters. "So you kind of remember most of them."

    This doesn't look like the first step in a legitimate power breakout, however.

    Although Garcia is working on an elevated launch angle, he's undercutting it with average exit velocity that's lower than ever at 81.7 mph. Thus, the 258-point difference between his expected slugging percentage (.367) and his actual slugging percentage (.625) is the highest in the National League.

    As far as the St. Louis Cardinals should be concerned, the silver lining is that Garcia will still be useful even after his power normalizes. He's always been a tough out, and his defensive versatility is an asset on an infield with lots of moving parts.

David Peralta, Arizona Diamondbacks

7 of 10

    Christian Petersen/Getty Images

    In 2017: 140 G, 577 PA, .796 OPS, 14 HR

    In 2018: 15 G, 71 PA, .946 OPS, 2 HR

    This isn't the first time David Peralta has been a good player. That's precisely what he was between 2014 and 2017.

    This is, however, the first time he's looked like a great player. His .975 OPS leads the Arizona Diamondbacks, which is no small feat considering that he shares a lineup with All-Stars like Paul Goldschmidt, A.J. Pollock and (when healthy) Jake Lamb.

    The catch is that Peralta's .452 batting average on balls in play (BABIP) is the highest of any player who's put at least 40 balls in play. Lo and behold, Peralta also owns the largest gap (118 points) between his actual BABIP and his expected BABIP (.334).

    One element of this equation is how Peralta isn't hitting the ball harder than usual, as his average exit velocity is at a career-low 87.7 mph. Another element is a ground-ball rate that remains well above the MLB average. He's thus infusing softer contact with batted balls that don't easily produce hits.

    To Peralta's credit, he is doing a better job of downplaying his pull side and making better use of the whole field. He should avoid a critical loss of BABIP luck if he keeps that up.

Dansby Swanson, Atlanta Braves

8 of 10

    Mitchell Layton/Getty Images

    In 2017: 144 G, 551 PA, .636 OPS, 6 HR

    In 2018: 17 G, 75 PA, .964 OPS, 2 HR

    After running into a brutal reality check in 2017, Dansby Swanson would seem to be back on the path to superstardom in his third season with the Atlanta Braves.

    And yet, here he is on this list.

    Swanson is doing better this year, in part because he's toned down his passivity. He's swinging more, and the fruits of that effort include improved exit velocity (90.5 mph) and a higher launch angle (9.7 degrees).

    The "yeah, but..." is that Swanson's aggressiveness hasn't been been of the controlled variety. His out-of-zone swing rate is up and his in-zone swing rate is down. His walk rate is a casualty of that.

    Swanson is thus putting a greater emphasis on keeping his BABIP up. That hasn't been a problem so far, as his .450 BABIP is the highest among all hitters who've put at least 50 balls in play. Trouble is, he has the same issue as Peralta in that his expected BABIP (.360) lags way behind.

    And despite his improved contact, Swanson may be lucky to be one of eight NL hitters with 10 or more extra-base hits. Of the bunch, his expected slugging percentage on extra-base hits is the lowest.

DJ LeMahieu, Colorado Rockies

9 of 10

    David Zalubowski/Associated Press

    In 2017: 155 G, 682 PA, .783 OPS, 8 HR

    In 2018: 20 G, 89 PA, .970 OPS, 5 HR

    DJ LeMahieu is a lifetime .302 hitter who won a batting title in 2016 (.348) but has never hit more than 11 homers in any season. So, it's certainly of interest that he's already almost halfway there in 2018.

    The underlying cause of LeMahieu's home run surge would seem to be that he's gotten more powerful. Check out his exit velocity on line drives and fly balls compared to years past:

    • 2015: 92.5 mph
    • 2016: 93.0 mph
    • 2017: 92.5 mph
    • 2018: 98.9 mph

    That last figure is better than quite a few notables, including Bryce Harper.

    But while the Colorado Rockies veteran may be hitting like a slugger, he's not swinging like one.

    His 1.5 degree launch angle is proof that he still cares not for swinging up at the ball. He remains a ground-ball hitter first and foremost. And while he is pulling more balls, his preference is still to go up the middle. Even at Coors Fields, habits like these aren't conducive to power.

    In time, LeMahieu will go back to being merely one of the best pure hitters in MLB. Alas.

Didi Gregorius, New York Yankees

10 of 10

    Elsa/Getty Images

    In 2017: 136 G, 570 PA, .796 OPS, 25 HR

    In 2018: 17 G, 73 PA, 1.216 OPS, 5 HR

    Didi Gregorius has been the best hitter in a New York Yankees lineup that also features Giancarlo Stanton, Aaron Judge and Gary Sanchez. And in some ways, it makes total sense.

    "Sir Didi" has suddenly transformed from a wild swinger into an ultra-disciplined one. That's helped him rack up 10 more walks (14) than strikeouts (4).

    Gregorius is also getting into the thick of the launch-angle craze. His has been getting bigger every year, and now it's downright huge at an average of 23.5 degrees. Between that and his pull habit, the lefty has just the swing for hitting home runs at Yankee Stadium.

    But therein lies the rub:

    • Home: 1.879 OPS, 5 HR
    • Road: .702 OPS, 0 HR

    These numbers will even out in the long run, but they get at how Gregorius' power swing still doesn't come with a ton of power. His 93.5 mph exit velocity on air balls is good, but short of elite. That helps explain how the 262-point gap between his expected slugging percentage (.542) and his actual slugging percentage (.804) is by far the biggest of any hitter.

    Gregorius thus fits into the same mold as LeMahieu. He's great, but not this great.


    Stats courtesy of Baseball Reference, FanGraphs and Baseball Savant.