In December last year, Japanese baseball sensation Shohei Ohtani signed the largest professional sports contract ever. 

Ohtani, signed a 10-year, $US700 million ($1 billion) deal with the Los Angeles Dodgers, toppling the eye-watering deals signed by Lionel Messi during his time at Barcelona and Cristiano Ronaldo's lucrative deal with Saudi club Al Nassr. 

Less than 12 months later, Ohtani has already provided rich dividends on that deal for the Dodgers, completing the first 50-50 season in Major League Baseball history.  

The feat has many experts calling Ohtani, a two-time MVP, the greatest player to ever swing a baseball bat, yes, surpassing iconic names such as Babe Ruth and Barry Bonds.

What is a 50-50 and has Ohtani ever come close before?

The two 50s in a 50-50 stand for home runs and stolen bases. 

Even if you're not a baseball aficionado, you've likely heard of what a home run is, so we won't spend time breaking that down. 

A stolen base requires a little more explanation. A stolen base occurs when a runner advances to the next base without the aid of any other actions. 

The most usual occurrence for a stolen base is when a runner advances while a pitcher is preparing to pitch the ball. 

While a successful stolen base can be a game changer, it is also a risky play and requires a runner who is quick and has near-perfect timing.

Prior to this season, Ohtani's previous season high for home runs was the 46 he hit while playing for the Los Angeles Angels in 2021. He also hit 44 homers in 2023, his last season for the Angels.

In his first year with the Dodgers, Ohtani has become a much more prolific base stealer. His 51 stolen bases for the season dwarfs his previous season-best mark of 26 which came in the 2021 season.

Has anyone else ever come close to a 50-50?

Simply put, no. Over 23,000 players have taken the field in the MLB over the last century and a half, and not a single player has reached the mark Ohtani has.

To put his achievement in perspective, Ohtani became only the sixth player in MLB history to join the 40-40 club, that is to score 40 home runs and steal 40 bases in the same season.

Jose Canseco was the first player ever to do this when he hit 42 home runs and stole 40 bases in 1988 for the Oakland Athletics.

Canseco and Ohtani are joined in the 40-40 club by Barry Bonds (1996), Alex Rodriguez (1998), Alfonso Soriano (2003) and Ronald Acuña Jr (2023).

The 40-40 club is so rare because very few players possess both the power to hit home runs and the speed to steal bases regularly. 

For example, Hugh Nicol holds the MLB record for most stolen bases in a single season with 138 in 1887, but he hit just one home run in that season.

Bonds holds the single-season record for most home runs, having hit 73 in 2001, but stole just 13 bases in the same season. 

There have been just 72 30-30 seasons.

Ken Williams of the St. Louis Browns was the first to achieve the feat in 1922, the second season after the end of the Dead Ball Era. No one else reached 30-30 until the New York Giants' Willie Mays in 1956 and '57.

How did Ohtani bring up the magical mark?

It was only right that Ohtani set the record mark in a record-breaking performance for the Dodgers.

Ohtani hit three homers and stole two bases as the Dodgers thrashed the Miami Marlins 20-4 on Friday morning AEST. He hit his 49th homer for the season in the sixth inning, his 50th in the seventh and his 51st in the ninth.

The 30-year-old went a perfect 6-6 for the game (six hits from six base appearances) and also had 10 RBIs (runs batted in, occasions where a teammate on base was able to run into home base courtesy of one of Ohtani's hits).

Ohtani became the first MLB player to hit three home runs and steal two bases in a single game. 

The Japanese superstar reached the second deck in right-centre on two of his three homers against the Marlins. In the sixth inning, he launched a 1-1 slider from George Soriano 133m for his 49th.

Ohtani hit his 50th homer in the seventh inning, an opposite-field, two-run shot to left against Marlins reliever Mike Baumann. Then, in the ninth, his 51st travelled 134m to right-centre, a three-run shot against Marlins second baseman Vidal Brujan, who came in to pitch with the game out of hand.

Ohtani took care of the stolen bases earlier in the game, swiping his 50th in the first and his 51st in the second.

The Japanese superstar led off the game with double against Edward Cabrera and swiped third on the front end of a double steal with Freddie Freeman, who reached on a walk.

Ohtani has been successful on his last 28 stolen base attempts.

He reached the 50-50 milestone in his 150th game. Ohtani was already the sixth player in major league history and the fastest ever to reach 40 home runs and 40 stolen bases in a season, needing just 126 games.

What has the reaction been to Ohtani's historic feat? 

Ohtani's performance against the Marlins set the baseball world alight on social media. 

Dodgers writer Noah Camras declared Ohtani's game against the Marlins "one of the greatest" performances in MLB history. 

Ohtani's feat wasn't lost on Canseco, the first man to join the 40-40 club. 

Already the consensus best player in baseball whose accomplishments as a pitcher and batter outpaced even Babe Ruth, Ohtani reached new heights as an offensive player while taking the year off from pitching.

The two-way star has played exclusively at designated hitter this season as he rehabilitates after surgery a year ago for an injured elbow ligament.

Preparation was a key to Ohtani becoming the first member of the 50-50 club. He regularly huddled with the team's hitting coaches and studied video of opposing pitchers to understand their tendencies with hitters and baserunners.

"I see all the work he puts in," Dodgers catcher Will Smith said recently. "It's not like he goes out there and it's too easy for him. He works harder than anybody. He scouts really hard. He's playing a different game so it's fun to see."

Ohtani appeared to make the 50-50 mark his mission. He increased the frequency of his base-stealing attempts and in turn his success rate went up.

But that may not be the case next year when he returns to the mound.

"He's not pitching this year so I think he is emptying the tank offensively," manager Dave Roberts said. "I do think the power, the on-base (percentage), the average, I think he can do that as a pitcher. He's done something pretty similar like that with his OPS. But as far as the stolen bases go, I'm not sure about that."

Ohtani's teammates have enjoyed watching him crush home runs and scamper around the bases.

"I'm honestly kind of trying to learn from him just seeing the way he goes about his day-to-day business. He's very consistent, the same demeanour throughout," outfielder Tommy Edman said recently. "I think that's why he's such a good player."

Third baseman Max Muncy added, "Every night I feel like he does something that we haven't seen."

With AP