Another Reason to Avoid Giants Hitters

It’s a well-established fact that AT&T Park is one of the worst ballparks in the major leagues for offense. That’s why, despite putting up a 132 wRC+ over his last 1,500 or so plate appearances, Brandon Belt is not a very valuable fantasy first baseman. It’s also why Buster Posey, a catcher with a career 136 wRC+, has never really been worthy of a top-10 pick on fantasy draft day.

In recent years, however, a new and troubling trend has emerged for the Giants offense. While the league has been on an historic home run tear the last year and a half or so, the Giants have not kept up. In fact, they’ve done the opposite: they’re hitting more ground balls (and fewer fly balls) than just about any other team in baseball.

Ground balls are almost always worse than fly balls, even for a team that plays in a cavernous ballpark like the Giants. Since 2014, Giants hitters have a .245 AVG, .263 SLG, .223 wOBA, and 45 wRC+ on ground balls at home. On their fly balls at home, however, they have a .226 AVG, .598 SLG, .332 wOBA, and 119 wRC+ since 2014.

While the team batting average is actually higher on ground balls, the slugging percentage, wOBA, and wRC+ are so, so much worse. This is strong evidence to the effect that even a team that plays in an extreme pitcher’s park is not better off hitting ground balls — flies seem to be indisputably better no matter what.

It would be one thing if the Giants hit a ton of line drives, the best of all batted ball types, but their 21.1% line drive rate since 2014 is just the 8th-highest in the NL, only 0.1% better than the league average.

The following chart illustrates the problem:

While the league is steadily trending in the right direction, the Giants are dashing the opposite way. Fly balls are good and ground balls are bad, yet the Giants are currently running the highest non-pitcher GB/FB ratio in baseball at 1.59.

Ground ball and fly ball rates stabilize after about 80 balls in play, too, so we’re right around the point where the 2017 data is significant, and it’s ugly for the Giants both collectively and individually.

Five of the Giants’ top fantasy hitters — Posey, Hunter Pence, Belt, Joe Panik, and Eduardo Nunez — are running above-average and/or career-high ground ball rates this year. Note that the league average ground ball rate is 44.0% (pitchers excluded).

Posey has hit ground balls on 49.2% of his balls in play this year. Last year, his ground ball rate was 48.6%, and the two years before that it was 43.9% and 41.9%, respectively, so he’s trending in the wrong direction. To make matters worse, Posey has just 12 home runs and a .435 slugging percentage in the past calendar year (602 plate appearances), and just five home runs and a .401 slugging percentage in 361 plate appearances since the last year’s All-Star break.

Another Giants hitter struggling to lift the ball and hit for power is Pence, who has always hit a lot of ground balls. In roughly 6,000 career plate appearances, Pence has a 51.6% ground ball rate. This year, however, he’s hitting grounders 57.0% of the time, and it was 54.8% in 2016. Pence’s career fly ball rate is 32.4%, but it’s just 28.5% since 2016.

Joe Panik is also running a career-high ground ball rate. His career average is 46.1%, but this year it’s at 50.6%.

Eduardo Nunez is the worst culprit of all. His 60.0% ground ball rate this year is among the very highest in baseball, and, despite his speed, it hasn’t been a good thing. Nunez’s career ground ball rate is 49.7%, but last season he found success by hitting grounders at his lowest rate, and fly balls at his highest rate, since 2013. This year, however, he seems to have abandoned that approach entirely, opting for a heavy dose of grounders. His fly ball rate of 22.2% this year is more than 10% lower than his career average.

To further illustrate what an extreme ground ball rate can do to a hitter’s overall performance, here is the list of the 10 hitters with the highest ground ball rates this season (updated after the conclusion of Sunday’s games):

The median wRC+ is just 74 for this group, and not one single hitter has managed a wRC+ of 100 or better. It’s an entirely different story for the 10 players with the lowest ground ball rates this season (again, updated after the conclusion of Sunday’s games):

While there are some below-average performers, the median wRC+ for this group is 119. Even on the very extreme end, the median wRC+ for the players with the 10 lowest ground ball rates is 45% better than the median for the players with the top 10 ground ball rates.

Getting back to the Giants, even Belt has caught the virus. He is an unlikely candidate, too, because last year he had the lowest ground ball rate (26.3%) and the 9th-highest fly ball rate (46.0%) in all of baseball, and he rode those ratios to a career-best .374 wOBA.

This year, however, Belt has a 40.6% ground ball rate that’s 6.5% higher than his career average, and a 34.4% fly ball rate that’s 6.6% lower than his career average. He’s still managed to put up a .362 wOBA thus far, but the rest of the Giants haven’t been so fortunate.

The Giants offense (pitchers excluded) has the worst wRC+ (77) in the National League. While they’re bound to improve over the course of the year, it’s no secret why they’re scuffling. They’ve hit an NL-worst 18 home runs this year, five fewer than the next closest team, and they’ve scored just 91 runs, also the worst in the league.

Quite simply, it’s hard to score a ton of runs (or win games, for that matter) when you’re not driving the ball and hitting homers and your opponents are. Giants pitching has allowed 28 home runs (at a very good rate of 1.04 HR/9), but the offense has hit just 18 home runs in 27 games. That’s a formula for failure.

The Giants are hitting more ground balls and fewer fly balls while the rest of the league is smartly trending the other direction. It’s hard to believe that the trend for the Giants is just a random phenomenon.

Perhaps the Giants have faced an unusually high amount of quality sinkers. Or perhaps Giants coaches or front office personnel preach keeping the ball out of the air because of their big home ballpark. AT&T Park is one of the hardest places to hit, especially for power, so it would be forgivable (at least for the coaching staff) if they told their players to avoid hitting the ball in the air. A simple look at the numbers, however, reveals that ground balls are a far worse than fly balls, even for teams like the Giants.

Whatever the cause, the collective and individual ground ball rates of Giants hitters is something to watch moving forward. Several major league hitters have turned their careers around and become superstars by intentionally hitting the ball in the air and avoiding grounders like the plague, but the Giants seem not to notice or care. Unless they can reverse this trend, Giants hitters should be discounted even more than they were in the past, when they were docked heavily for their expansive home ballpark. For whatever reason, the ground ball bug has bit them, and until that changes, they’re going to continue to struggle to keep up offensively with the rest of the league.