For a long time, the scouts from Major League Baseball have viewed the Kiwoom Heroes’ clubhouse as a lavish showroom. This Korean club has served as a dependable source of MLB prime prospects, developing and exporting the club’s most talented players. Just recently, they sent outfielder Jung-hoo Lee, who signed with the San Francisco Giants for a whopping $113 million. Infielder Hyeseong Kim also joined the club, signing with the Los Angeles Dodgers. So, when scouts started watching third baseman Song Sung-mun this season, the script felt familiar.

Instead of heading to the US, Song Sung-mun is staying home. The Kiwoom Heroes announced on Monday that they have signed their captain to a huge 6-year contract extension that is worth up to 12 billion won (around $8.7 million). The deal is a full guarantee and keeps the 29-year-old star with the team till 2031, which also puts to rest any thoughts of an MLB transfer. The contract is a record breaker, which is the largest ever guaranteed deal for a non-free agent position player in the KBO.

The decision was hard to come by, but it was a total turnaround from what Song had been saying before. As recently as June, he was publicly put forth as a player who didn’t have major league aspirations. He didn’t see himself as a good fit, telling reporters that his play wasn’t at the major league level.  “To be honest, I’m not at the level of a player to play in the MLB. Going to the US is unrealistic at my age,” he stated.

The turning point came in a phone call with former with former teammate and established MLB star Ha-seong Kim. After viewing Song’s interviews, Kim got in touch to give out some important advice. “He asked me why I felt that way, told me I was worthy of the challenge, and encouraged me to take heart,” Song recalled. Kim framed the opportunity as a no-lose situation, that the experience in itself was priceless regardless of the result.

Kim’s motivation turned out to be the pivotal moment for Song. He transitioned from completely ignoring the notion to accepting an “open ending.” He started to inform the press that he might entertain a relocation if sufficient opportunity arose for him subsequent to the season. But the certainty offered by the Heroes proved more powerful than the unknown of the MLB market.

By signing this extension, Song turned his back on the official KBO-MLB posting system. In that process, all 30 MLB teams would have had a chance to approach him after the season. If he signed, the Heroes would have got a large release fee, which is 20% of the first $25 million of his guaranteed contract value, 17.5% of the next $25 million, and 15% of any amount over $50 million. It’s the system that brought in the money for the team from the leaves of their past stars, and the road that he didn’t choose.

This landmark agreement represents a perfect alignment of interests, which secures the player’s and the franchise’s future in a way that a move overseas could not.

A Perfect Match: Why Both Sides Said Yes

For the Kiwoom Heroes, this was a strategic and necessary investment. CEO Wie Jae-min reported that with the free agent market “expected to heat up,” the club had to act quickly. He put the extension forward as a big step for the team. “This contract… is indicative of the level of our trust and expectations in the player,” Wie said. “To realize our mid- and long-term plans, signing Song Sung-mun to an extension was a must.”

For Song, the contract provided security along with an opportunity to create a legacy. He said he was glad the team believed in him. “I will try to be a positive influence for my teammates,” Song said in a statement. “I will wear the name of the team with pride and reward our fans with my best effort in every game.”

Song is now part of a long history of KBO players who have faced this life-changing decision. Many have opted to step up to the plate for the MLB, with varying outcomes. Pitcher Ryu Hyun-jin became the first Korean-born pitcher to start a game in the World Series. Infielder Ha-seong Kim won a Gold Glove with the Padres. They demonstrate the amazing possibilities of achieving success and fame that come with going through the best league in the world.

However, there are also cautionary tales. Star player Byung-ho Park did not live up to the same standard as his great promise in Minnesota (.191 BA) as he did in the Korean Baseball Organization. And he went back after one season. In the case of Jung-ho Kang at the plate, injury and other off-field problems derailed his career. These stories highlight the significant risks Song would have faced. By staying, he chose a guaranteed legacy over a high-risk, high-reward gamble. A decision that will define his career for years to come.