Superstar outfielder Juan Soto and the New York Mets are in agreement on a 15-year, $765 million contract, sources told ESPN on Sunday night, the largest deal in professional sports history.

The deal includes an opt-out after five years and no deferred money, sources said. If Soto chooses not to opt out, his deal will go up $4 million per year — from $51 million to $55 million — for the remainder of the contract, meaning the total value could exceed $800 million.

The contract also includes a $75 million signing bonus, sources said.

The 26-year-old Soto, whose prodigious power, discerning eye and postseason bona fides created a free agent frenzy among some of the game’s blue-blood teams, joins a Mets squad that made a surprising run to the National League Championship Series last season and is now poised to contend for years to come.

Following a standout season with the New York Yankees in which he guided the team to the World Series and finished third in American League MVP voting, Soto’s presence in the free agent market drew significant interest. While the Mets, Yankees, Toronto Blue Jays, Boston Red Sox and Los Angeles Dodgers were among the final bidders, teams across the financial spectrum — including the lower-payroll Kansas City Royals and Tampa Bay Rays — explored signing Soto, covetous of his special bat.

The Yankees fielded a competitive offer — a 16-year, $760 million deal with an annual average value of $47.5 million and no deferrals, sources told ESPN’s Buster Olney. Ultimately, though, Soto decided on the Mets.

In seven major league seasons, the 6-foot-2, 220-pound Soto has hit .285/.421/.532 with 201 home runs and 592 RBIs and has accumulated more than 36 wins above replacement. Despite below-average corner-outfield defense, Soto distinguished himself with the best command of the strike zone since Barry Bonds, allowing him to hunt and punish pitches over the plate.

The $765 million guarantee exceeds the $700 million the Dodgers gave two-way star Shohei Ohtani on a 10-year deal last winter. While 97% of Ohtani’s salary will be deferred for 10 years, Soto’s deal contains no deferred money, lifting the net present value of his deal well above Ohtani’s.

The contract, agreed upon after a monthlong sprint that included face-to-face meetings, three rounds of bidding and agent Scott Boras leveraging Soto’s talent to drive the price to stratospheric levels, further validated Soto’s decision in 2022 to turn down a 15-year, $440 million offer from the Washington Nationals, who had signed him as a 16-year-old out of the Dominican Republic and watched him blossom into one of the best players in the major leagues. Soon after Soto rejected the Nationals’ overtures, they traded him to the San Diego Padres, starting a whirlwind 2½-year stretch that saw Soto moved twice.

He had arrived in Washington at 19 years old, a touted prospect who rocketed through the Nationals’ system and debuted earlier than expected because of injuries to outfielders on the major league roster. In the first at-bat of his first start on May 21, 2018, Soto crushed a first-pitch fastball 422 feet to the opposite field. Over the next six seasons, he would hit more than half his home runs to center field and left field, a rare ability that epitomized his gifts at the plate.

In a game where the imbalance between pitching and hitting places offense at a premium, Soto illustrated year after year why so many evaluators revered his skill set. During his first full season in 2019, he hit three home runs in the World Series to lead the Nationals to an upset win over the Houston Astros. In the shortened 2020 season, Soto hit .351/.490/.695 with 13 home runs in 47 games and would likely have won the National League MVP award had a positive COVID-19 test and later an elbow injury not caused him to miss about a quarter of the season.

Soto thrived in 2021, walking 145 times, the only person this century to reach that threshold outside of Bonds. Washington’s attempts to keep him in the nation’s capital included multiple extension offers, all of which Soto turned down, leading to one of the biggest trades in baseball history at the 2022 deadline: Soto and first baseman Josh Bell to the Padres for outfielder James Wood, left-hander MacKenzie Gore, shortstop CJ Abrams, outfielder Robert Hassell III and right-hander Jarlin Susana.

In San Diego, Soto shook off a mediocre-by-his-standards final two months to rebound with a career-high 35 home runs and an NL-leading 132 walks in 2023. With free agency a year away and San Diego’s attempts to extend Soto rebuffed, though, the Padres dealt him and center fielder Trent Grisham to the Yankees at the 2023 winter meetings for right-handers Michael King, Drew Thorpe, Randy Vasquez and Jhony Brito, and catcher Kyle Higashioka.

With the Yankees, Soto found the best version of himself. Batting second in front of Aaron Judge, he hit .288/.419/.569 with 41 home runs, 109 RBIs, an American League-leading 128 runs and 8 WAR. During the postseason, he was even better, slashing .327/.469/.633 with four home runs, nine RBIs and 12 runs in 14 games. His extra-innings home run in Game 5 of the AL Championship Series sent New York to its 41st World Series.

The timing couldn’t have been better. The two most sought-after free agents this century have been Alex Rodríguez, a 25-year-old shortstop whose $252 million contract in 2000 doubled the previous high, and Ohtani, a boundary-breaking phenomenon whose skills and marketability helped him exceed the previous standard by a sum larger than Rodriguez’s entire deal.

Prior to Soto’s contract, the longest deal in baseball history was Fernando Tatis Jr.’s 14-year pact with San Diego. The prospect of locking in the remainder of Soto’s prime — not to mention any milestones he could pass on the way to the Hall of Fame — appealed strongly enough that the teams in the bidding were willing to match the 15 years he received.

If any résumé warrants that sort of commitment, it’s Soto’s. He is already a four-time All-Star, four-time Silver Slugger, batting champion, Home Run Derby champion and World Series champion. His .421 career on-base percentage is tops in baseball since he debuted. His .532 slugging percentage is seventh. His .953 OPS and his 158 wRC+ are fourth. Soto’s 769 career walks are the most for a player through his age-25 season — 99 more than second-place Mickey Mantle.

The sustained excellence allowed Soto to thrive in the arbitration system, in which he made $54 million over the past two seasons. Add that to his new $765 million deal and Soto reaped $379 million more than he would have made had he accepted the Nationals’ final extension offer.

“You cannot base a centurion player’s value on other players,” Boras said at the time. “You have to base it on financial markets.”

The markets spoke loudly on Sunday night. And they said the largest deal ever belongs to Juan Soto.

ESPN’s Jorge Castillo contributed to this report.