The Slapdick Hitting of the Rays

“We gave Pham up for Renfroe and a damn slapdick prospect?” Blake Snell bemoaned live on Twitch. He was reacting to a trade between the Rays and the Padres that took place during the 2019-20 offseason. Snell’s annoyance caused a bit of controversy – he ended up reaching out to said prospect, Xavier Edwards, to smooth things over – but it also popularized the term, to the point that it’s now part of our baseball lexicon.

What does it mean exactly, though? Urban Dictionary informs us that a “slapdick” is more or less an incompetent person (to put it nicely), but that doesn’t feel quite right in a baseball context. For me and presumably others, a slapdick hitter is someone who doesn’t hit for power and earns his keep by spraying the ball around – someone like Nick Madrigal. Although the Rays currently do not roster Madrigal, they do have this: As of this writing, their hitters collectively have the highest BABIP (.264) and wRC+ (57) on groundballs. A slapdick hitting team.

If your sabermetric senses are tingling, I understand. Due to the fickle nature of BABIP, continued success on grounders is a tenuous endeavor. It’s entirely possible the Rays have gotten lucky over the past few months. But in the spirit of FanGraphs, I began to wonder if there’s an extra dimension to this. The numbers, in fact, do posit an interesting idea – that the Rays have set themselves up for success on grounders, more so than most teams this season.

How does an individual, let alone a team, maximize production on the least valuable type of batted ball? First, it’s good to know that unlike line drives and fly balls, straightaway and opposite groundballs usually end up as hits more frequently than their pulled counterparts. It’s long been this way, perhaps because the gap between second and third receives a stronger fortification than the gap between second and first. In recent years, the infield shift has weakened the power of the up-the-middle hit, but it’s also strengthened the power of the opposite-side hit. There’s a strong incentive to hit ‘em where they ain’t. We can see which teams are doing just that, graphing the percent of each team’s grounders that aren’t pulled:

The Rays are above-average in this metric, but they aren’t on top. Not every hitter is adhering to a slapdick approach, a detail I’ll expand on later, so the team loses out on rate and volume. What matters, though, is whether the efforts have translated into results. And so far for the Rays, they’ve not only sowed but also reaped:

This is where they stand out. In terms of batting average, the distance between the first-place Rays and the second-place Mariners is equal to that between the Mariners and the 10th-place Marlins, whose hitters triumphed in the earlier chart. Isolate opposite groundballs, and the story is similar –  the Rays are averaging a whopping .541, a figure much greater than their expected average of .240. They’re also not losing out on straightaway groundballs, which have returned an average of .256 that’s in line with an expected average of .250.

But this is where the discussion of luck re-enters. It’s a known fact that expected stats don’t take batted ball direction into account; even so, a BA minus xBA differential of .301 seems absurdly high. There’s a bit more nuance to this, however, or else what you’re reading wouldn’t have existed. Case in point: Groundballs from faster hitters tend to perform better than what xBA would estimate, despite the metric factoring in a batter’s seasonal Sprint Speed as of January 2019. Courtesy of the amazing Alex Chamberlain, here’s a representation of how xBA on grounders changes as Sprint Speed does:

AVG (green) v. xBA (red) *on ground balls* by sprint speed (ft/sec), 2017-20

interestingly but intuitively, contact quality degrades from bigger power hitters to smaller speedsters

however (also intuitively), marginal speed more than offsets marginal declines in contact quality pic.twitter.com/1mHsdFb3HL

— Alex "Oxlade" Chamberlain (@DolphHauldhagen) June 25, 2021

As Alex adds in the tweet, contact quality doesn’t matter all that much if you’re fast enough. The point regarding speed ties back to the suggestion that the Rays aren’t uniformly slapdick. You won’t see Mike Zunino, Ji-Man Choi, or Austin Meadows hit the ground running often – they’re busy launching balls into the air. Taylor Walls, Mike Brosseau, and Brandon Lowe occupy the middle of the slapdick spectrum. In my view, the Rays hitters who define this concept are Kevin Kiermaier, Yandy Díaz, Joey Wendle, Manuel Margot, and yes, Randy Arozarena, with Brett Phillips and Francisco Mejía as fringe candidates. The quintet is diverse, but it has one trait in common:

Those are some fast hitters, alright. The exception here is Díaz, but he more than makes up for his pace by being prolific; since 2020, he leads the five with 116 non-pulled grounders and an average exit velocity of 87.3 mph on them. In general, speed has played a pivotal role in transforming would-be outs into singles for this team. Here’s Wendle showing off his wheels on an infield single:

And here’s Arozarena beating out what’s more often than not a fantastic play by the shortstop, Xander Bogaerts:

At the moment, the slapdick hitting of the Rays boils down to a) avoiding the pull side and b) having enough speed to outrun throws from infielders. But there’s a third, more obscure factor that’s the most fascinating of them all. Tropicana Field, it turns out, is a groundball paradise. Since the start of the Statcast era, every grounder hit there has returned an average of .261 against an expected average .234. Pulled or not, slow or fast runner, it doesn’t matter – there’s a certain quality about the Trop that is conducive to grounders performing above expectations.

A few years ago, an article at SB Nation’s DRaysBay took note of this quirk, surmising that the stadium’s artificial turf “plays faster” and is therefore responsible for erratically moving bouncers. But the team implemented a new turf in 2019, and perhaps not coincidentally, the difference between BA (.236) and xBA (.233) normalized. The following year, however, the average soared again, suggesting the Trop had returned to its original state despite no news of changes to the artificial turf. That trend has continued into this year, too.

Whatever the reason, the Trop is still one of the best parks in which to hit a groundball. Are the Rays taking advantage of this? Let’s consider the groundball rates of our five hitters this season, split between home and away:

There are differences, but it’s doubtful that any of them are statistically significant after taking sample size into account. Looking back to 2020, the data is even murkier – for example, Wendle’s groundball rate is higher away than at home, whereas Kiermaier’s home rate is around 15 percentage points higher than his away rate. Maybe there’s something here, but it’s likely noise. I’d imagine it’s difficult to encourage select hitters to alter their approach in a specific environment, and the hassle involved isn’t worth the potential benefits.

It’s also difficult to tell whether there’s any intent behind the Rays being good at hitting grounders. Díaz’s transformation into a slapdick hitter has been well documented, but what about the others? Margot is certainly pulling the ball less compared to 2020. Wendle has been his usual self, and although Kiermaier’s offensive output has taken a tumble, the same can be said about him. You might think Arozarena has suddenly begun to traverse the slapdick path. The truth is that his batted ball data hasn’t changed, but one season featured a 46.7% HR/FB rate, and the other, more recent one does not.

Ultimately, the bigger picture here is that Rays hitters are playing to their strengths. There’s no point in convincing Joey Wendle, a career .258 xwOBA hitter on fly balls, to produce more of that batted ball type, especially when the Trop is such a fantastic environment for him. In a similar vein, there’s no point in convincing Mike Zunino to hit dribblers when he’s capable of producing majestic home runs. Specialization isn’t a revolutionary concept – I’m not preaching Rays exceptionalism here – but they execute it well, helping them squeeze out just enough runs, it seems, to secure narrow victories.

I assume there’s some amount of luck influencing these groundballs. There always is. But I also buy that there’s some amount of sustainable success! And it’s fun to imagine that acquiring Xavier Edwards was a declaration of sorts. Oh Blake, your incensed self had no idea what would come.