When Shohei Ohtani first arrived in the United States, his promise was simple and yet seemingly impossible, even arrogant. He could be MLB's first real two-way player since Babe Ruth.

For three seasons, that goal looked unobtainable. Ohtani won AL Rookie of the Year in 2018, but tore his UCL in the process. He hit at a well-above average clip in 2019, but didn't throw an inning as he rehabbed from Tommy John surgery. He made it back to the mound in 2020, but got hurt again while hitting .190 at the plate.

No sport quite grinds you down quite like baseball's 162-game regular season, and Ohtani was basically trying to play two of those seasons at once. Just playing a full two-way season would have been an accomplishment.

That's why what Ohtani did in Year 4 still doesn't seem real, even as he put the finishing touches on his campaign on Sunday. That's why what Ohtani has done has broken everything we know about the limits of a baseball player.

Shohei Ohtani's final 2021 numbers

With one last addition to his stats, a leadoff homer in Sunday's season finale against the Seattle Mariners (video above), here is where we have arrived with Ohtani.

His final hitting numbers: 639 plate appearances, a .257/.372/.592 slash line, 46 homers, 103 runs, 100 RBI. He had 4.8 WAR by Baseball-Reference's calculations entering Sunday, 5.0 WAR per FanGraphs.

His final pitching numbers: 23 starts, a 9-2 record, 130 1/3 innings, a 3.18 ERA, 151 strikeouts (10.8 strikeouts per nine), 1.090 WHIP, 4.1 WAR via Baseball-Reference, 3.0 WAR via FanGraphs.

For six months, Ohtani was in the Angels' lineup nearly every day while regularly taking a turn in the rotation, though the Angels did their best to give him extra days of rest and pushed back some starts due to health concerns. Even if he didn't pitch enough innings to qualify for the ERA title, what he's done has been unprecedented. Yes, even considering Ruth.

Ohtani has surpassed even Babe Ruth

It bears emphasis: No player in the history of baseball has ever been as good at hitting and pitching as Shohei Ohtani was this season.

While Ruth has long been the lone two-way star in MLB's vaunted history, he was really a two-way player for only a short time. The Boston Red Sox used him sporadically as a pitcher in 1918, the year they started letting him hit full-time, and only pitched him for half the season in 1919. The next year, Ruth was traded to the New York Yankees and would make only four starts on the mound for the rest of his career.

That's not to say Ruth's time as a two-way player wasn't brilliant; it was. He hit .322/.456/.657 with a then-MLB record 29 home runs while posting a 2.97 ERA in 133.1 innings (17 games, 15 starts) in 1919, still one of the most impressive seasons ever. Those pitching numbers come with a pretty significant caveat, though, as he was playing in the dead ball era. His 102 ERA+ that year implies Ruth was only two percent better than the average MLB pitcher that year, while Ohtani had a 141 ERA+ in 2021.

Ruth still finished with more WAR that season than Ohtani thanks to his hitting, but it's probably fair to say Ohtani better delivered on the idea of a two-way player by being decidedly above-average on both sides of the game. And that's to say nothing of the quality of competition Ohtani is facing vs. Ruth's.

All the other ways Ohtani has impressed

The fun thing about Shohei Ohtani is that even if he were two different players, we would still be talking about him (them?) this season.

Ohtani the hitter wasn't just an above-average hitter, he was one of the most physically impressive sluggers in MLB. Per the Angels, he leads all of MLB in homers hit 110 mph or harder with 24. He is also one of six players in American League history to hit 45 homers and eight triples in a season, joining Babe Ruth, Lou Gehrig, Joe DiMaggio, Jimmie Foxx and Jim Rice. Every one of those other players is in the Hall of Fame.

For most of the season, Ohtani led all of MLB in homers, though eventually fell in the AL race behind Salvador Perez and Vladimir Guerrero Jr.

Ohtani the pitcher had one of the best pitches in the majors this year with his splitter. Per Baseball Savant, batters hit only .087 against the pitch with a .119 wOBA and a 48.5 whiff rate. His slider was another weapon, with batters hitting .193 and whiffing 31.1 percent of the time. Pair those offerings with a fastball that averaged 95.6 mph this season and you have a pitcher everyone wants to watch.

As if all that isn't unfair enough, keep in mind that Ohtani — all 6-foot-4, 210 pounds of him — is also one of the fastest players in the majors. He stole 26 bases this season, and it goes without saying he is the first player with 20 homers, 20 stolen bases and 20 innings pitched in a season. His 28.8 feet per second sprint speed puts him ahead of players like Lorenzo Cain, Javier Baez and Wander Franco.

Forget a five-tool player, Ohtani may be a legitimate 10-tool player. Seven at the very least.

What's next for Shohei Ohtani?

Showing he could last a full season as a two-way player was step one for the 27-year-old Ohtani's quest to become one of baseball's greats. Next up is showing he can do it for more than one season.

Even though Ohtani made it to the season finale, he still had some health stumbles along the way. Getting through another season and pitching more than 130 1/3 innings would be massive in showing that the two-way Ohtani is viable long-term. If not, Ohtani's bat can certainly play at designated hitter for foreseeable future, and you have to wonder how much better a hitter he could be if he focused on his time at the plate.

This all matters because we now only have two seasons until the circus that will be Ohtani's free agency. Teams might not want to invest in the two-way idea long term, but they will definitely pay up for his present and near future if he's still producing in 2023.

Ohtani himself opened up a bunch of speculation that he could leave the Angels when he said this earlier this week:

Obviously, the Angels — even when they have an all-time great or two — haven't been a winning team. The dynamic is literally a meme at this point. The clock appears to be ticking on changing that, lest they lose a player currently at the center of the baseball universe.