A week before the All-Star break, DJ LeMahieu is leading the Yankees in bWAR, by more than a win over second-place Gleyber Torres. If you’d told a Yankees fan that before the season, they would probably—after asking if you didn’t have something better to do with your time machine—have taken it as a sign that the Bronx Bombers’ season had gone down the tubes. LeMahieu is a fine player, but the offseason acquisition emerging as the best performer on a team with World Series ambitions was not exactly Plan A.

But here in the present, that’s exactly what’s happened. LeMahieu is hitting .345/.392/.534, leading the American League in both hits and batting average. This past weekend, the 30-year-old infielder was named to his third All-Star team, but halfway through the season, he’s already blown past his full-season bWAR totals from either of those previous campaigns. Earlier this week, USA Today’s Bob Nightengale suggested that LeMahieu might be the front-runner for AL MVP, which is a bridge too far for me as long as Mike Trout’s hitting .297/.452/.606, but certainly LeMahieu would deserve down-ballot consideration if the season ended today.

All this from a player the Yankees not only signed to be a complementary piece, but signed in lieu of pursuing a more expensive infielder who’s usually in the MVP conversation (i.e. Manny Machado). Nobody could’ve seen this coming.

When the Yankees signed LeMahieu to a two-year, $24 million contract, the deal made sense for both sides, as LeMahieu got eight figures to provide the Yankees with much-needed infield depth. With shortstop Didi Gregorius on the shelf until June and incumbent third baseman Miguel Andújar fielding the hot corner like he’s wearing cast-iron oven mitts superglued together, the Yankees required more from their utility infielder than the average club. LeMahieu could play second and third well, wouldn’t strike out much, and would hit for a high average with a few doubles.

Buying a $12 million–a-year utilityman instead of a $30 million–a-year superstar third baseman is somewhat un-Yankee-like, but it fits with the modern era of baseball in which the all-out pursuit of championships takes a backseat to staying under the luxury tax.

The drop-off from Machado to LeMahieu was supposed to be gigantic. If you’d asked me before the season to name the most overrated player in baseball, I probably would’ve gone with the former Rockies second baseman. LeMahieu wasn’t a bad player with Colorado—he’s usually been within about a win of league average—so much as he excelled in areas that mattered a great deal in the 1990s (batting average, raw stolen base totals, defense as measured by Gold Gloves), but in the 2010s require more context to understand.

In that context, LeMahieu suffered. Before joining the Yankees, he’d hit .300 three times and even won a batting title in 2016, but he didn’t walk much and, despite playing half his games in Coors Field, posted a double-digit home run total just twice in six full seasons, with a career high in home runs of just 15. He’d posted an above-average wRC+ just once in his career, and despite reaching double digits in stolen bases four times, his career success rate was a hair under 66 percent, which is horrendous for a base stealer of such high volume. His defense at second was quite good, but was it really good enough to beat out Javy Báez for the past two Gold Gloves? Only once from his debut until his departure from Colorado last fall did LeMahieu exceed 3.0 bWAR.

Maybe my evaluation of LeMahieu’s game was a little uncharitable. There’s still a lot of value to average production at second base, even if LeMahieu’s numbers didn’t match his reputation. The Yankees didn’t think they’d need him to be José Altuve, they thought they’d need him to be Marwin González, and that much LeMahieu was more than capable of doing. And because the Yankees needed a solid utility infielder even more than they’d realized, the LeMahieu signing might end up being the difference in the AL East.

Not only did Gregorius miss the first two months of the season, Andújar quickly joined him on the IL, as did Troy Tulowitzki, whom the Yankees signed this offseason as another option at shortstop. As injuries cascaded across the Yankees roster, LeMahieu found himself playing third base in relief of Andújar, then back at second to cover for Torres, who’d moved over to fill the vacancy at shortstop. Now that Gregorius is back, LeMahieu’s playing some third, some second, and even making the occasional spot start at first base, a position he’d played for just a few innings at a time when he was with the Rockies.

Whatever defensive position LeMahieu’s played, he’s hit. He kicked off his season with back-to-back multihit games, cooled off a little near the end of April, and then got back into gear and has kept his batting average above .300 ever since April 26. Right now, he’s hotter than ever; through Monday, LeMahieu is riding a streak of six straight multihit games, the third-longest multihit game streak of any player this season, and LeMahieu’s third multihit streak of four games or more this year. Over those six games, LeMahieu is 18-for-28 with eight extra-base hits, including three home runs, and has raised his batting average 23 points in the space of a week.

Those three home runs brought LeMahieu’s season total up to 12, just three shy of his career high with three months left to play. For a player who counted a lack of power among his biggest weaknesses, this home run surge has been a huge development.

For most of his career, LeMahieu was essentially a slap hitter who made tons of contact but didn’t hit for extra bases very often. Players with this profile are the prime candidates to benefit from the Swing Plane Revolution—Justin Turner, Daniel Murphy, and Matt Carpenter are just a few of the dozens of former light-hitting infielders who started uppercutting and traded singles for doubles and home runs as a result. If I’d known nothing about LeMahieu except the player he was in, say, 2015, and the fact that he was having a breakout year, I’d have assumed that he’d embraced the elevate-to-celebrate approach.

LeMahieu’s batted-ball profile did change somewhat in the recent past, but it changed between 2017 and 2018, and his batted-ball and plate-discipline numbers look remarkable only compared with where they started. In 2017, he had a GB-FB ratio of 2.82, the second highest in baseball. In 2018, it dropped to 1.68, the 21st highest in baseball, and he set new career highs in home runs and isolated power, marks he’s on pace to break once more this season. Out of 160 qualified hitters this year, LeMahieu has the 10th-highest ground-ball-to-fly-ball ratio. He’s still a fairly extreme ground ball hitter, just not quite as extreme as he was two years ago.

Compared with Carpenter, who went from a player with an average GB-FB ratio to the most fly ball–happy hitter in the league, this doesn’t look like an extreme change. But while Carpenter went from normal to extreme, LeMahieu’s gone from extreme to normal. Almost every plate discipline and batted-ball stat that LeMahieu’s changed the past two years has taken him from an extreme end of the spectrum to somewhere close to average. He was 115th out of 140 in swing rate in 2018, but he’s up to 92nd of 160 this year. In 2017 he had the highest opposite field rate in baseball by far; in 2018 he dropped to 15th, and he’s tied for fourth this year.

LeMahieu hasn’t stopped being himself, he’s just become a less extreme version of himself, and as a result he’s hitting the ball harder and for more power than he ever has outside of the 2016 season in which he won the batting title.

There are two reasons this didn’t get as much press last year: The first is that changes on a first-place Yankees team tend to get noticed more than performance changes on a second-place Rockies team. The second is that while the underlying numbers and power stats made their big leap last year, LeMahieu wasn’t putting up eye-popping batting averages in 2018. And while LeMahieu is hitting the ball slightly harder in 2019, the main difference is luck.

In 2018, LeMahieu posted a .298 BABIP in Coors Field, which has an outfield the size of Madagascar. This year, despite moving to a smaller park in a tougher division, his BABIP is up to .375, which is the fourth-highest mark in baseball, 29 points north of his career average. If he kept that mark up over a full season, it would be the 26th-highest full-season BABIP of the past 10 years, out of 1,462 individual player seasons. He’s also outhitting his xwOBA by 23 points, according to Baseball Savant.

But so what if he’s getting lucky? By putting up these first-half numbers while playing important defensive positions as the rest of the team collapsed around him, LeMahieu’s already all but justified the balance of his contract. Furthermore, even if he does regress substantially in the second half, this will still probably end up being the best season of his career. For the Yankees, who rolled the dice by not pursuing bigger fish in free agency, this breakout season could not have come at a better time.

Stats current through Monday’s games.