Is this rookie having best start to career ever?

Yordan Alvarez began the 2019 season by destroying the Pacific Coast League, batting .343/.443/.742 with 23 home runs in 56 games at Triple-A Round Rock.

The Astros finally called him up on June 9, a couple of weeks before his 22nd birthday, and a bit less than three years after acquiring him from the Dodgers for reliever Josh Fields. In his MLB debut that day, Alvarez homered against the Orioles. In his next game, he homered against the Brewers.

Alvarez has not stopped yet, and the results are historic.

His three-homer, seven-RBI game on Saturday at Baltimore was a wakeup call to anyone who hasn’t been paying attention, and his 1-for-11 performance in the Astros’ series against the White Sox that concluded Wednesday counts as a significant slump.

Houston begins a new series Thursday night at Oakland, and if Alvarez is in the lineup, it will be his 50th MLB game. It also will cap what might be the best 50-game debut by a hitter in at least the past 80 years.

That’s a strong statement, but through 49 games, Alvarez owns a .339/.422/.694 slash line, which produces a park-adjusted wRC+ of 190 (90% better than league average). He has bashed 14 doubles and 17 homers, while driving in 52 runs.

Among the 300 players who have collected at least 200 plate appearances this year, Alvarez ranks second in batting average and on-base percentage, and first in slugging, OPS and wRC+. Granted, other league leaders such as Mike Trout, Cody Bellinger and Christian Yelich have well over twice as many trips to the plate, but that’s impressive company nonetheless.

Most similar batter to Mike Trout this season based on batted ball profiles?

Yordan Alvarez https://t.co/1MYREOxv1c pic.twitter.com/qnjPocn4wP

— Daren Willman (@darenw) August 13, 2019

What’s more, no batter on record in recent baseball history has put up louder numbers in the first 50 games of his career, according to MLB.com research.

Highest OPS, first 50 career games
Min. 150 plate appearances, since 1940
1) Yordan Alvarez (2019 HOU): 1.113 (through 49 G)
2) Willie McCovey (1959 SF): 1.110
3) Albert Pujols (2001 STL): 1.104
4) Bernie Carbo (1969-70 CIN): 1.089
5) Gary Sanchez (2015-16 NYY): 1.067
6) Tony Oliva (1962-64 MIN): 1.061
7) Fred Lynn (1974-75 BOS): 1.046
8) Ryan Braun (2007 MIL): 1.044
9) Alvin Davis (1984 SEA): 1.042
10) Bob Hazle (1955-58^): 1.039
^Played with CIN, MLN, DET

Such a hot start at the plate doesn’t guarantee anything. But McCovey is a Hall of Famer, and Pujols will be. Braun is enjoying a long and highly productive career, similar to those of Lynn and Oliva, who both generated upwards of 40 WAR. Carbo and Davis remained solid hitters, but neither quite remained at the heights he achieved as a rookie. Time will tell with the 26-year-old Sanchez, who has had his ups and downs so far, including two All-Star selections.

(Hazle is something of an outlier, who played just 110 career games, dealing with injuries after an excellent partial season with the 1957 Braves.)

Alvarez also has become one of eight hitters in MLB history to go deep as many as 17 times in his first 50 career games -- with one game to go before he reaches that milestone. His 52 RBIs are the fourth-most through 50 games, behind only 1950 AL Rookie of the Year Walt Dropo (57) and two more recognizable names: Joe DiMaggio (55) and Ted Williams (54).

The numbers above aren’t park- and league-adjusted, and Alvarez is flourishing at a time when home runs are flying across baseball, with the MLB-wide slugging percentage the highest its been in any season other than 2000.

That may be giving his numbers a bit of a boost in comparison to some players of the past, but there is plenty behind Alvarez’s results to suggest more good things to come.

• Despite being a rookie and a powerful slugger, Alvarez’s strikeout rate is only slightly above the MLB average, and his whiff rate on swings is actually lower than average -- similar to those of Cody Bellinger, Manny Machado, Rafael Devers and Freddie Freeman. His walk rate is above average.

• When Alvarez makes contact, it’s quality contact. His average exit velocity and hard-hit rate both rank in the top 20 among MLB hitters with at least 100 batted balls this season, according to Statcast. The left-handed-hitting slugger stands among the MLB leaders since his debut with 13 balls hit at 110 mph or harder, including five home runs. A blast he hit in Houston off Rangers lefty Mike Minor left his bat at 112.2 mph and set an Astros Statcast record by flying a projected 474 feet.

• Before a rare off game Wednesday that saw him hit three grounders, Alvarez ranked in the top 10 in the Majors by producing a line drive or fly ball on 61.8% of his balls in play. That’s helped him produce 24 barrels -- contact with an optimal combination of exit velocity and launch angle -- putting him in the top 10 in MLB since his debut.

• Alvarez has hit lefties just as well as righties, and has thrived on more than just fastballs. Of his 17 home runs, 11 have come against breaking balls or offspeed pitches, and he is slugging better than .800 against them.

If those trends are any indication, Alvarez could turn the excellence of his first 50 games into a historic rookie campaign. Alvarez, who might now be the AL Rookie of the Year Award favorite, currently has the best park- and league-adjusted offensive performance for a rookie in modern MLB history.

Highest single-season wRC+ for a rookie
Min. 200 plate appearances, since 1900
1) Yordan Alvarez (2019 HOU): 190
2) Willie McCovey (1959 SF): 185
3) Joe Jackson (1911 CLE): 184
4) Frank Thomas (1990 CHW): 178
5) Aaron Judge (2017 NYY): 172

The league always adjusts. Maybe the series in Chicago was the beginning of that, and Alvarez will have to figure out a way to fight back.

But for now, Alvarez is sitting in rare territory, and the first-place Astros are reaping the rewards.