2019 MLB Draft Guide: Learn to Use GB, FB & LD Rates

Human beings love labels. It’s just something we’re drawn to. Look no further than baseball to find players with labels. Billy Hamilton ’s a stolen base threat (and not much else). Joey Gallo is a big home run guy. He’s clubbed 40 in each of the last two seasons, but he also comes with an extremely high strikeout rate. Labels are actually pretty useful too because it’s good to have an opinion on every player. It doesn’t need to be an elaborate one, but something simple or a quick label is good. It’s smart to apply labels when drafting your team because some players are more adept to contributing more in categories/rotisserie leagues while other guys help out more in points leagues.

Labels will also apply to hitters and pitchers based on their ground ball, fly ball, and line drive rates. It’s a simple enough concept too: pitchers more prone to fly balls are often considered to be fly ball pitchers (duh). Those that can induce ground balls are obviously ground ball pitchers. The same rule of thumb can be applied to hitters as well. And it’s worth noting most players have been trying to put the ball in the air more often as part of the fly ball revolution that baseball has experienced in recent years. The phrase “chicks dig the long ball” is a bit unfair in my opinion because everybody digs the long ball. And there’s a direct correlation between fly balls and home runs, so we’ll start there because it makes for a good segue.

Fly Ball Rate

As noted above fly ball hitters tend to hit the ball out of the ballpark. Ground balls sure as hell aren’t leaving the ballpark anytime soon although this play from the Mets resulted in a bases clearing almost inside-the-park home run (I say “almost” because there’s no way it was ruled as such). But we’ll get to grounders later on. For now let’s take a look at the players who led the league in fly ball percentage last season.

All ten players hit at least 20 home runs with eight of them clubbing at least 27. And even if you extended the list further you’d still find power hitters on the list. So putting the ball in the air leads to more home runs in general. But also be on the lookout for HR/FB rate. This is simply the percentage of fly balls that result in home runs. Take Rhys Hoskins for example, over half of the balls he put in play were in the air, but he only hit 34 home runs. So it’s reasonable to understand that his HR/FB rate was just 16.0%, which was good for 44^th in the league. On the other end of the spectrum, Christian Yelich clubbed 36 home runs in his first season with the Brewers. His fly ball percentage in 2018 was in line with his rate from 2017 and 2016 in his time with the Marlins. In 2018 his FB% was at 23.5%, but his HR/FB rate was an insane 35.0% which was much higher than his last season in Miami (15.3%). Yelich certainly benefitted from a ballpark change, but given that his FB% was in line with previous seasons we can stand to reason his HR/FB rate should come back down a little more and his 2019 power could regress somewhat. Don’t forget, he went on an absolute tear in the second half of last season and that helped him win the National League MVP. Yelich put less balls in the air than Hoskins, but hit more out of the ballpark. It just doesn’t seem repeatable. So in this day and age it’s actually a good thing to be a fly ball hitter amidst the revolution if there’s a reasonable HR/FB rate that correlates. If you’re in a fantasy baseball league that relies heavily on counting stats (home runs, RBI, runs, etc.) then fly ball rate is a good metric to look at if trying to find power.

Being considered a “fly ball pitcher” is normally not the greatest sign for those toeing the rubber. However, there are outliers. Justin Verlander led the league last season with a 51.4% fly ball rate. Based on what we know about hitters and flyball rates, you’d think Verlander gave up a ton of home runs as well, and to an extent, he did. However, he surrendered 28 home runs over 214 innings and his 11.1% HR/FB rate isn’t terrible. Fly balls aren’t as much of a problem for pitchers as line drives rate and we’ll touch on those shortly. But fly ball pitchers are more prone to home runs, especially if they’re giving up harder contact. Max Scherzer had a similar profile to Verlander last season in that he was closer to the top of the list in FB%, and like Verlander, he didn’t give up a lot of hard contact (28.6% to Verlander’s 29.1%) and had a low HR/FB rate (9.7%).

But other pitchers that were exposed to fly balls weren’t as fortunate as the two previous elite arms. Dylan Bundy , Mike Fiers , Jakob Junis, Julio Teherán , and Tyler Anderson all gave up a lot of fly balls last year and because they also gave up harder contact to opposing hitters they were victims of the long ball. But you can survive as a fly ball pitcher. Would you prefer to be more of a ground ball pitcher? Perhaps because ground ball pitchers keep the ball in the yard. Fly ball pitchers aren’t a death sentence especially if pitching in the right ballpark. The real killer for pitchers is on deck…

Line Drive Rate

A high line drive rate is what all hitters attain for and it’s what pitchers try to prevent. Line drives typically go further and don’t hang in the air as long so naturally they’ll lead to more hits. Line drives equate to more offense in the form of extra base hits and runs. There’s a bit of a grey area when it comes to line drives and fly balls though. To the naked eye, sometimes it is clear when there’s a line drive and a fly ball. However, there are rare instances when it is difficult to decipher. Most times, examining fly ball and line drive rates together could be a smart course of action because they lead to more power and offensive production. But just because you boast an elite line drive rate doesn’t mean you’re an elite hitter. Freddie Freeman , Matt Carpenter , and Paul Goldschmidt all ranked in the Top 20 hitters for LD% but so did Chris Taylor , Billy Hamilton , José Peraza , and Matt Duffy . So look at line drive rate in conjunction with fly ball rate as well as hard contact rate. A higher LD% with a lower hard-hit rate usually yields minimal results. Line drives need to be accompanied with hard contact. A little smoke helps to create the laser shots.

From the rubber, Luis Severino led the league in line drive rate at 25.9%. He’s still a top-tier pitcher so don’t let it discourage you from drafting him. He didn’t exactly finish the season strong last year. From July 7^th through the rest of the year he had 32.0% line drive rate compared to his 21.3% rate in April, May, and June. He had serious regression in the second half of the season plus he gave up harder contact in the second half as well. Don’t take Severino off your draft boards, he’s still a phenomenal pitcher that should be on everybody’s draft board. Then again other pitchers that surrendered line drives at a higher clip include Marco Gonzales , Derek Holland , Tyler Anderson , and Andrew Heaney all surrendered line drives at a higher clip. Jon Lester had the second-highest line drive rate behind Luis Severino and that could be the result of his best days being behind him. Again, like offensive players line drive and fly balls should be examined with how much hard contact pitchers are surrendering to opposing hitters. While line drives may be fluky, hard contact rarely is.

Ground Ball Rates

Ground ball rates apply mostly to starting pitchers but hitters aren’t entirely excluded. Grounders typically go for more hits than fly balls do, but they don’t yield the same power results as fly balls or line drives obviously. Another reason some experts seem to think Christian Yelich will regress is because 51.2% of his balls in play were ground balls. That mark was his lowest in his previous five seasons and even at 51.2% it was still the 12^th-highest GB% in 2018. Here were the hitters with the highest GB% from a year ago:

As you can see, ground balls don’t necessarily lead to an elite OPS. Christian Yelich was the only player with a Top 12 GB% that posted a Top 50-OPS. And none of the 11 players above him necessarily jump off the page as a power hitter. Lorenzo Cain still contributed 90 runs and 30 steals, but he hit just ten home runs and drove in 38 RBI. Dee Gordon also stole 30 bags, but scored just 62 runs. Eric Hosmer signed with the Padres last offseason coming off back-to-back 25-home run campaigns in 2016 and 2017. He finished with just 18 last year. Ian Desmond was a decent fantasy contributor despite the high rate of ground balls and low OPS. He hit 22 home runs, stole 20 bases, scored 82 runs, and drove in 88 RBI. However, he did get the benefit of playing in Coors Field. So while players can still contribute with lower ground ball rates, most of the time they won’t deliver a high power return for your fantasy team.

For pitchers, ground balls are actually okay to be associated with. It’s not as fascinating as being an elite strikeout pitcher though, so it helps to lend perspective. Ground ball pitchers are better at keeping the ball in the field of play. While grounders can lead to more hits than fly balls, they limit damage for the most part. Aaron Nola was one of the best ground ball pitchers in the league last season. In fact, his career rate is 50.9% so the 50.6% rate from a year ago seems legitimate and in line with his career body of work. Because of his elite ground ball rate it’s no surprise that he posted a 0.72 HR/9 and a 10.6% HR/FB rate. Dallas Keuchel had a higher GB% rate (53.7%) than Nola last season and yielded a similar 0.79 HR/9 and 11.3% HR/FB rate. He did have a higher ERA (3.74 to Nola’s 2.37), but Nola’s a better strikeout pitcher and Keuchel’s BABIP to opposing hitters was 49 points higher than Nola’s (.300-to-.251). So you can be a contributor in fantasy even if you give up more ground balls. Sometimes when deciding to stream a pitcher a respectable ground ball rate is worth keeping an eye on. You won’t find elite arms when trying to stream a pitcher so finding a guy that keeps the ball in the park is a tried and true method to streaming pitchers.

Batted ball metrics are incredibly useful tools when trying to assess the players you want on your team. But as mentioned above they should be examined with hard hit data to see if the numbers correlate or if a player may be in line for positive or negative regression. With the recent fly ball revolution taking the league by storm, ground ball, fly ball, and line drive rates are as important as ever and you should expand your horizons and look at these a little more when evaluating mid-to-late-round power hitters.