Manny Machado hasn’t had that season yet. You know the one—when he optimizes all of his prodigious baseball talents in one splendiferous season that alters common perception of his already lofty ceiling. It’s Bryce Harper in 2015, reshaping—if just momentarily—the Trout-vs.-Harper debate; it’s Jake Arrieta that same year, setting records with every start. Machado has delivered good seasons before, even great ones, but he’s yet to produce a paradigm-shattering one that catapults him up to Mike Trout atop the baseball hierarchy.

Though Machado has a pair of six-WAR seasons (using FanGraphs WAR) and a couple of Gold Gloves, he hasn’t mastered all his flaws at the same time. He suffered injuries; he lacked sufficient plate discipline; he didn’t have Harper’s power or Trout’s consistency. Machado’s best MVP finish, fourth, is also Trout’s worst result, and 31 different active position players have at least one season with more wins above replacement than Machado’s best-ever total.

Through the first quarter of the 2018 campaign, it’s apparent that this season might be that season for Machado. Through Tuesday’s games, Machado ranked third in the majors with a 187 wRC+, behind only Mookie Betts and Trout, and he was tied for fifth among position players with 2.4 WAR. Those prior concerns are gone: He’s healthy and disciplined and full of power at the plate, where he either holds or is tied for the AL lead in all three Triple Crown categories. As he prepares to enter free agency next winter and perhaps sign a record-high contract, Machado has managed the best and longest-sustained performance of his already bright career—at least on offense.

At its most basic, successful hitting arises from three tenets at the plate: Swing at strikes, don’t swing at balls, and make hard contact. Machado had followed those principles piecemeal before, but for the first time as a big leaguer, he is accomplishing all three at once.

The most noticeable change in Machado’s offensive profile is that he is both walking and striking out at career-best rates. Before this season, he had struck out 2.5 times for every walk in his career, but so far in 2018, those two totals are exactly the same (23 each). He isn’t swinging much less overall, but he’s fiddled with the relative frequency of his cuts, and he’s now swinging more at pitches inside the strike zone and less at pitches outside than he did earlier in his career. Among 169 qualified hitters, Machado has the sixth-largest gap between his in-zone and out-of-zone swing rates, just behind Joey Votto and Freddie Freeman and just ahead of Harper.

In his career, Machado has swung at just more than 30 percent of pitches outside the strike zone; last year, that rate was 31.9 percent. This season, he’s down to 26.2 percent; the only other time Machado had a better-than-average chase rate over a full season was 2015, which also brought his previous high-water marks for offensive production and WAR. Avoiding chasing would-be balls is especially important in 2018, as pitchers routinely target the areas outside the strike zone leaguewide, and as Machado personally sees a career-low percentage of pitches inside the zone.

He still hits too many pop-ups—which are about as sure an out as a strikeout—and enough of his walks have been intentional (an AL-leading seven of his 23) that those gains might prove illusory. But those are small worries for a hitter who’s been as hot as Machado, with the underlying numbers to support that performance, even if Machado himself might call those numbers “dumb-ass stats.” He’s also been aggressive, but now he’s refined that approach to a more selective aggression. Anybody placing near Votto on a plate discipline leaderboard is doing something right.

And when Machado does swing, he both makes contact at an above-average rate and connects with authority. His average exit velocity—both on all balls in play and balls hit in the air—is a near-perfect match for Betts’s, and his hard-hit rate sits at a career high. Machado is combining his best-ever plate discipline with his best-ever power output, and it’s resulted in a further bevy of career bests across the board: batting average, on-base percentage, slugging percentage, wRC+, and many more. He’s displayed a penchant for easy highlights, too, with four multi-homer games already. One of those outbursts victimized Corey Kluber, against whom Machado so resoundingly crushed a pitch that the reigning Cy Young winner began berating himself before Machado had even completed his swing.

But while Machado finally produces a complete season at the plate, another flaw has appeared in his overall profile. Playing as Baltimore’s everyday shortstop for the first time in his career, Machado has exhibited a surprisingly leaky glove that separates him from the very upper crust of MLB talent in 2018. Trout and Betts aren’t just among the best hitters in baseball; they also provide positive value on defense and are so impactful because of their well-rounded play. Trout is an average or better defender at a premium position, and Betts is an extraordinary defender at a middle-of-the-spectrum position.

That latter description once also applied to Machado, who played shortstop in the minor leagues but moved to third base upon his MLB promotion because incumbent shortstop J.J. Hardy rated as a plus defender. Machado performed spectacular feats with his glove at the hot corner and ranked as either the best or second-best third baseman (depending on the statistic, which juggled him and Nolan Arenado) in the majors through the last five years. During that span, only nine other players at any position were more valuable defenders than Machado, and every one was either a shortstop or catcher. The top 25 included nine shortstops, eight catchers, and five center fielders—the three hardest positions to master—plus Machado, Arenado, and Dustin Pedroia.

Machado was such a smooth and skilled defender at third base that a move back to his natural position with Hardy finally gone this season made sense for both the Orioles, who might have seen their star player gain even more value, and Machado himself, on the eve of his free agency. But thus far in 2018, Machado has once again displayed unique defensive abilities—just in the opposite direction. Among the 25 shortstops who have played at least 250 innings this year, he ranks last in both advanced defensive metrics displayed at FanGraphs, with negative-5 defensive runs saved and a negative-3.6 ultimate zone rating. In the latter stat, Machado is so far back from the pack that 24th-place Trea Turner is as close to 11th place as he is to Machado. And if placing last among his peers isn’t enough, the most damning fact about Machado’s early defensive returns is that his fielding numbers on a per-game basis place him near Derek Jeter at the Yankee shortstop’s defensive nadir.

Machado’s arm isn’t the problem—with plays like this in his past, his arm will never be a problem—but his lateral movement and range are. During spring training, one scout told ESPN about his confidence in Machado’s ability at shortstop, “Because of positioning and the shift, I think range is overrated now anyway. He still has elite body control, and his hands are as special as they were when he was at third base.” That scout might want to revisit his statement: Machado’s range slipped at third base last season before derailing at his new position in 2018. The numbers say that he has displayed the second-worst range of any fielder at any position this season, ahead of only Colorado’s Charlie Blackmon running around centerfield in Coors.

Of course, a player making Machado’s transition would expect to see his numbers relative to his positional average decline; third base is populated largely with players who for some reason or another weren’t strong enough defenders to remain at shortstop. This is the concept behind positional adjustments: Shortstops as a group are better defenders than other infielders as groups because that position is more challenging, so an average shortstop should receive more relative credit for his fielding than an average third baseman.

When calculating player value, FanGraphs uses positional adjustments to compare players, and the positions are weighted such that a player should theoretically be able to move from one spot to another without losing any value. Historical data shows that a generic defender would be about five runs worse at shortstop than at third base over the course of a full season, so player valuation models give shortstops five extra runs of credit to balance the two positions evenly. But even by this standard, Machado has performed far worse than those generic predictions would expect. Machado is on pace to finish not five runs worse after his switch, but between 15 and 25 runs worse. That’s a difference of one to two WAR, or the rough difference between a mere All-Star-caliber season and an MVP-worthy one.

Defensive stats take years to stabilize, so it would be imprudent to rush to judgment about Machado’s shortstop capabilities after even a full season, let alone seven weeks of data. But prudent or not, teams don’t have years to judge Machado’s adjustment at short, where it appears he wants to remain for years into the future. They have one year at a maximum before potentially investing in his future in free agency, and less than that if they’re thinking about trading for him this summer. The early defensive results, then, are alarming, as is the nearly nonexistent history of a player accomplishing a smooth transition to shortstop.

Research provided by The Baseball Gauge’s Dan Hirsch shows that in modern MLB history, only three players transitioned up the defensive spectrum from another position to shortstop when they had more career WAR than Machado. One was Honus Wagner at the dawn of the 20th century; one was Tony Lazzeri, who qualified via a technicality in the 1930s, as he played a plurality of games in his age-34 season at shortstop but spent that season mostly as a pinch hitter; and one was Gold Glove second baseman Bobby Grich, who played 52 games at shortstop in his injury-shortened 1977 season before moving back to his previous position.

That list yields two conclusions: first, that no player of Machado’s caliber has so much as attempted a move to short in more than 40 years, and second, that the only player of Machado’s caliber who moved to short and stuck there is the greatest shortstop in MLB history. The list of more recent players who attempted such a transition, even if they were worse than Machado at the time, is no more reassuring: It includes mostly utility infielders, with an odd appearance from the likes of Asdrúbal Cabrera, who was a minus defender at short on a nearly annual basis, and Michael Young, who has the worst fielding season for a shortstop on record.

The lack of precedent might somewhat overstate Machado’s difficulties if he wishes to remain at shortstop, as Machado played and excelled there in the minor leagues; it isn’t an entirely new undertaking. But despite his best dietary efforts, he’s also bigger now than he was as a teenager, and slower, and his athleticism manifests in a different fashion: Even acknowledging that Statcast’s sprint-speed metric isn’t perfect, the fact that it pegs Machado as the slowest shortstop in the majors, with the same speed as Pablo Sandoval, isn’t encouraging.

If he continues to hit near his current level, Machado can still succeed and contend for awards as a porous defensive shortstop. Derek Jeter did, and young Hanley Ramírez did with perhaps the most severe all-bat, no-glove profile for a shortstop in baseball history. Machado’s top-five WAR total in 2018 is proof of that possibility, as that ranking comes despite a negative from the defensive factor in the WAR calculation.

But every other player with WAR totals near Machado’s rates as both a positive offensive and defensive force, from dazzling shortstops like Francisco Lindor and Andrelton Simmons to sneakily deft defenders like Aaron Judge. A sturdy fielder gains more leeway for any slumps or broader decline at the plate, and an elite fielder simply has more ways to accrue value for his team. Were Machado hitting this well while also playing to his typical level at third base, he might be leading the league in WAR, or at least threatening Trout and Betts at the top. As is, he’s once again just below the highest rung, having arrived at that oh-so-close level by a different means than usual, sure, but having arrived at that same place all the same.

All statistics through Tuesday.