Update to The Board: KBO Prospects

The start of a new prospect list cycle provides a nice, natural time for a sweeping update of my analysis around the international prospects I think readers should know about. Some international pros have already inked free agent deals this offseason, while others have created great anticipation for an eventual move to MLB. In a month, a new class of international amateur players will begin to sign. This week, the International Players tab on The Board will be updated with new scouting reports and information concerning the various segments of the international player population, largely surrounding pro players in Asia and the contingent of teenagers mostly from Latin America who will sign in January. We’re going to publish these in batches throughout the week, with a focus on KBO players today, Japanese players thereafter, and international amateurs at the end of the week. Because they’ve already signed, we’ve also pushed info on Japanese pros Masataka Yoshida and Kodai Senga to The Board; the write-ups you’ll find there are my evaluations, and they each have their own transaction analysis article up at the site as well (I wrote Senga’s, while Justin Choi penned Yoshida’s).

This market is important because players coming to the U.S. from Asian leagues, including many whose pro careers began as MLB minor leaguers, often make an impact on big league contending teams. Chris Flexen 플렉센, Miles Mikolas, Brooks Raley 레일리, Yusei Kikuchi, Yu Darvish, Robert Suarez, Nick Martinez, Ha-Seong Kim 김하성, Pierce Johnson, Darin Ruf 러프, and Joely Rodríguez all either got their starts or made a stop in a top Asian pro league, and all were on an MLB playoff roster this season. The data generated by these leagues and warehoused online (including KBO stats here at FanGraphs), combined with my access to video analysis tools like Synergy Sports, and some time spent on the phone with baseball ops and scouting folks who cover (or are part of) international teams, means I can give readers a lay of the land in this space.

I’ll talk more about my approach in a minute, but first, let’s revisit the rules around signing international players. Seemingly in an effort to control expenditures in this market, MLB’s rules around signing international players have changed numerous times in recent years in ways that have dramatically reduced what top-of-the-market players get. For instance, the Red Sox gave 19-year-old Yoán Moncada a $31.5 million bonus in 2015. They paid a dollar-for-dollar tax on that bonus per the rules at the time (so $63 million total) and incurred non-monetary penalties as a result of exceeding the soft cap associated with the international signing processes of that era. Contrast that with Shohei Ohtani, who was 23 and had five seasons of pro experience when he signed after the 2017 season for $2.3 million (his NPB club received a $20 million posting fee). This is emblematic of how things have trended for players in the international space, both pro and amateur. A complete breakdown of the rules from the league itself (including some valuable context) can be found here. Readers should familiarize themselves with those rules, as they’ll be relevant for all of this week’s content, but the most important couple of lines for the purposes of this batch of scouting reports is the language that dictates where international amateur bonus restrictions end and true MLB free agency begins:

Foreign professionals — defined as players who are at least 25 years of age and have played as a professional in a foreign league recognized by Major League Baseball for a minimum of six seasons — maintain exemption from the international bonus pool.

That glossary entry also outlines the previous version of the rule:

Also of note: Previously, foreign-born players were granted exemption from the amateur-bonus-pool rules if they were at least 23 years of age with at least five seasons in a professional league recognized by Major League Baseball.

It’s conceivable that a 23-year-old could sign two long-term free agent contracts before they turn 30, but now that the required age is 25, it’s tougher to envision that happening. Plus, any 25-year-old signing a long-term contract is more likely to run into their decline years during the back end of their deal than the same player signing at age 23, and teams no doubt factor that risk into what they offer foreign pro players. Things have trended this way because CBA negotiations ultimately decide these rules, and MLB owners have incentive to change the rules in such a way as to reduce what they’re paying players, especially when the delta is in the tens of millions of dollars. The Players Association, meanwhile, lacks incentive to fight MLB on these particulars because everyone in the association has already gone through their draft/signing process and has incentive to cede ground in this arena if it means trading it for new ways for current MLBPA members to make more money. What long-term impact these trends will have on MLB’s ability to attract the world’s best talent away from foreign pro leagues (and avoid losing talent to them, especially Nippon Professional Baseball) remains to be seen. The rules tend to change more quickly than their impact can be assessed.

Let’s talk about some Korea-specific stuff since today’s drop of reports focuses on that group. The Korea Baseball Organization is a 10-team league that MLB personnel tend to equate with a Double-A level of play, largely due to the lack of MLB-quality velocity on the pitching side. Data on Synergy shows the average fastball velocity in Korea was about 89 mph in 2022. The league caps foreign player participation at three players per team (no more than two pitchers) and allows a maximum salary of $1 million for expats. The league had a power-hitting surge that really peaked starting around 10 years ago, but changes to the baseball and two changes to the strike zone, including changes that took effect for the 2022 season, seem to have curbed that. Only 39 KBO hitters with at least 300 PA in 2022 slugged .400 or more; in 2016, that number was 67.

The KBO player pages and leaderboards at this site were instrumental in doing an initial sift through the league for superlative performers, especially the precocious youngsters among them. You’ll no doubt recognize lots of the former MLB players and prospects who freckle the KBO leaderboard, many of them Quad-A-type hitters for whom the $1 million foreign player price tag represents an improvement to their up/down roster fringe existence in MLB. In addition to the high-end statistical performers who look the part on film, for the last couple of years I’ve done some digging on the KBO draft’s first rounders before this winter update. So many KBO first rounders are compact little strike-throwers with vertical arm slots who sit about 88-91. It’s rare for a domestic high schooler who looks like that to work their way onto our pre-draft radar and so, for the sake of brevity, even though it’s common for a player like that to go very high in the KBO draft, I’m learning to wait to put them on The Board. Chances are they won’t be on the MLB radar for a while, and the ones who do end up drawing notice let you know they’re there by throwing harder over time. As such, I’m much more likely to write up a position player, like first round shortstop Kim Min-Seok, in their draft year.

When a Korean teenage pitcher’s stuff is clearly better than what I’ve described, they tend to end up in an MLB system right away. For example, 18-year-old Shim Jun-Seok (more on him later this week) and his present mid-90s fastball opted to skip the KBO draft and become an international amateur free agent subject to bonus pool restrictions.