If you like watching professional baseball, the KBO (Korea Baseball Organization) League ought to be your thing right now. The general level of play isn’t the same as Major League Baseball or even Nippon Professional Baseball (NPB). But that misses the point entirely; it’s a very different atmosphere than Major League Baseball, with wild bat flips, crowd-participating cheer songs — when there actually is a crowd — and a kind of all-in style you don’t always see in the oh-so-serious major leagues. NCAA basketball and football are compelling watches in a similar way, even though nobody really believes that Gonzaga has a better roster than this year’s Cleveland Cavaliers or that LSU and Ohio State can truly hang with even the Cincinnati Bengals.
In MLB, there are always a large number of players on the fringe between the majors and Triple-A who have trouble getting sustained chances to stay in the majors because, well, teams are trying to win games. Japan has been a popular destination for these types for decades, and Korea has become an increasingly viable new baseball home for many American players, offering an opportunity to hone their craft for better pay, and with more flexibility, than in the American minors. Players like Eric Thames and Miles Mikolas came back from the KBO better players than when they left the U.S.
This year, there are 30 foreign-born players in the KBO League. Most are players from MLB, and quite a few will be familiar. Many of these players will succeed in the KBO, such as former Red Sox/Dodger Jerry Sands, who led the league in RBIs in 2019. Former Triple-A slugger Jamie Romak finished third in the league in home runs.
But what would happen if we sent our best player to play in Korea? What would a Mike Trout — or, more accurately, the Mike Trout — be able to put up numbers-wise in Korea?
The first thing to figure out is just how good the KBO is, from a competitive standpoint, relative to MLB. Luckily, unlike a league like the Chinese Professional Baseball League (CPBL), there has been quite a lot of exchange of players between the U.S. and South Korea. A number of players have also come from and to NPB, another league for which we have a lot of data for, and that helps us hone our educated guesses through the transitive property of baseball-ality.
Based on the data available, KBO appears to be somewhere between Double-A and Triple-A, on average, though the best players are more likely to be MLB-quality than your typical Double-A league; it’s harder to get “promoted” from KBO to MLB than it is from Double-A to MLB.
So what would Mike Trout’s career look like if he packed up his bat and headed to Seoul? The ZiPS projection system was prepared to tackle this question long before we had ever heard of COVID-19, leading me to be unusually prepared.
Trout would likely dominate KBO given the extent he dominated MLB in the 2010s. There’s simply no more complete player in existence than Trout. If anything, the surprise might be the shape of his KBO projections, which see his batting averages go up more than his raw power numbers.
There’s a reason for this: KBO isn’t the high-scoring league that it was just a few years ago. In 2018, KBO teams hit .286/.353/.450, scoring 5.6 runs per game. Pitchers had a collective ERA of 5.17 in 2018, a leaguewide ERA seen at no time in MLB history and not in baseball since the 1894 season, during the years that pitchers were adjusting to the mound being moved back to 60 feet, 6 inches.
After 2018, KBO was looking for a change and used de-juiced baseballs, something MLB seems unable to do despite owning Rawlings. Offense dropped overnight, with a 40% decline in homers, along with other smaller declines. So what happens if Trout plays in Korea and the KBO brings the live ball back? In that competitive environment, Trout’s projected numbers look much more video game-like:
Those 61 homers — in a shorter 144-game season, mind you — would be the most in a season in KBO history, edging Seung Yuop Lee, who hit 56 in 2003 for the Samsung Lions. There would be something poetic about Trout going to Korea and setting a home run record with the exact Roger Maris number that stood as the record for nearly four decades.
It seems extremely unlikely that Mike Trout goes to Korea, short of an unlikely, but at least possible, scenario in which MLB’s core business is crippled by a COVID-19 second wave and/or protracted labor discord. Still, it’s an interesting exercise, though I personally prefer us selfishly keeping Trout here for ourselves.