Statcast's Expected Weighted On-base Average (xwOBA) is an all-encompassing statistic that looks at a hitter's performance based on quality and quantity of contact.

Both a strong indicator of current and future offensive success, xwOBA generally features some of baseball's best hitters at the top of the leaderboard. Last year's top five featured Aaron Judge, Ronald Acuña Jr., Yordan Alvarez, Shohei Ohtani and Corey Seager, while the 2022 season featured Judge, Alvarez, Freddie Freeman, Juan Soto and Mike Trout. You get the point.

Through the first month of the '24 season, some of the best hitters by xwOBA are more or less who you'd expect: Ohtani, Soto, Alvarez and Mookie Betts all rank as top-10 hitters. Leading the Majors in xwOBA, however, is a player that baseball fans might not have even known a little over a year ago -- and still might not be fully familiar with.

Based on Statcast's top statistic for all-around offensive success, the Orioles' Ryan O'Hearn leads all qualified hitters with a .482 xwOBA.

The following numbers are entering Thursday's games.

So who is Ryan O’Hearn? In parts of five seasons in a platoon/bench role with the Royals, he hit just .219/.293/.390 (83 OPS+) as a first baseman, DH and corner outfielder. During the 2022-23 offseason, the Royals (coming off a 97-loss campaign), designated O’Hearn for assignment, then traded him to the Orioles for cash considerations. After beginning the season in Triple-A, O'Hearn debuted for the Orioles in mid-April and became one of the better hitters (122 OPS+ in 368 plate appearances) on a team that won 101 games and the AL East.

What O’Hearn is doing so far in 2024, however, is well beyond that level and a continuation of the breakout that started last season. O'Hearn is running an xwOBA near .500 (anything above .400 is considered elite) because he's doing everything at an extremely high level. Let's take a closer look.

High quality of contact

The 30-year-old O'Hearn is leading hitters with a .731 expected SLG, while his .352 expected BA trails only Ohtani (.373). O'Hearn's actual .300 batting average and .543 slugging percentage are still great but the underlying metrics suggest that there's more in the tank. O'Hearn's .403 wOBA is well below his .482 xwOBA -- making him one of the most "unlucky" hitters in the Majors.

What’s led to O’Hearn's ability to consistently produce quality contact? More of the same, according to the veteran.

“Just continuing the same thing we were doing last year,” O’Hearn told MLB.com about changes coming into the season. “Trying to put my body in a good position to be adjustable and handle any pitch.”

O’Hearn talked about the importance of producing hard contact at optimal angles, something he’s done much better this season. His 14.3 percent barrel rate is a 4.2 percentage-point improvement over last year, while O’Hearn’s sweet-spot percentage (batted ball between 8-32 degrees) has jumped 6.2 points to 41.3 percent. O'Hearn ranks in the 87th percentile or better in barrel rate, sweet-spot rate and average exit velocity.

“I’ve always hit the ball hard but hitting it hard at better launch angles is the key. That’s how you do damage,” O’Hearn said. “It doesn’t matter how hard you hit it if you hit it right into the ground.”

Better swing decisions

It hasn’t just been the drastic improvement in quality contact, though. He’s made significantly more contact on the whole and is making better swing decisions this year.

O’Hearn 2023 vs. ’24

Strikeout rate: 22.3% / 8.9%
Whiff rate: 23.3% / 22.8%
2-strike contact rate: 77.7% / 86.7%
Walk rate: 4.1% / 11.4%
Chase rate: 30.9% / 18.4%

Among qualifying hitters, O’Hearn has had the largest drop in chase rate and strikeout rate and the second-largest improvement in walk rate. While O’Hearn isn’t swinging and missing much less, he’s offset that with his ability to make contact with two strikes.

“[It’s a] small sample size so far but I'm seeing the ball and being aggressive in the areas that I’m looking to hit the ball that day,” O’Hearn said about his approach this year. “[I’m] being aggressive in those zones but having the discipline to be able to take pitches even though they may be borderline. It may cost me a strikeout here or there but that can translate into more walks.”

In terms of identifying one major shift with O'Hearn's plate discipline, it's really been about swinging less on the whole. O'Hearn has been one of the most passive hitters in the Majors with a 40.0 percent swing rate, which would be a career-low rate and is tied for 25th-lowest among hitters with 75 plate appearances. He's also seeing first-pitch strikes just 50.6 percent of the time, tied for the sixth-lowest rate in the Majors.

When that pitch comes in the zone, though, O'Hearn is doing damage. His .966 OPS on in-zone pitches trails only 25 hitters.

A limited role

The caveat to O'Hearn's production is that the Orioles have employed him in a very strict platoon role against right-handed pitching.

Dating back to 2023, only 34 of O'Hearn's 447 plate appearances have come against left-handed pitching -- including just five against lefties in 79 plate appearances this year. Whereas O'Hearn has faced lefties in 7.6 percent of plate appearances dating back to last year, others like Ohtani, Alvarez and Soto are in the lineup every day, regardless of pitcher handedness.

That's not to diminish O'Hearn's development and production as a hitter. Most pitchers, after all, are right-handed so there are ample opportunities for O'Hearn to be in the lineup. It just means his overall numbers might be skewed when comparing him to the Ohtanis and Sotos of the world. It also means the Orioles can't rely on him as an everyday bat (luckily, that's not much of an issue for a stacked Orioles lineup).

Undoubtedly, the Orioles are in their current position mainly due to their development of young studs over the last half-decade. That alone would make for a competitive team but the Orioles have also excelled in acquiring under-the-radar players like O'Hearn. Anthony Santander was another sneaky acquisition as a Rule 5 pick in 2016 that is one of the longest-tenured O's and a middle-of-the-order bat.

The Orioles always saw the potential in O'Hearn's bat but even this might be more than the organization expected. O'Hearn's development this year makes the Orioles that much more dangerous in the short term as they look to repeat as AL East champions. If these improvements are even close to real, O'Hearn could be one of baseball's top hitters for one of the league's best teams.