X
Lost password?

Don't have an account?
Gain Access Now

X

Receive free daily analysis

NFL
NBA
NHL
NASCAR
CFB
MLB
MMA
PGA
ESPORTS
BETTING

Already have an account? Log In

X

Forgot Password


POPULAR FANTASY TOOLS

Expert Advice
Articles & Tools
Import Your Leagues
Daily Stats & Leaders
All Pitcher Matchups
Compare Any Players
Compare Any Players
Rookies & Call-Ups
24x7 News and Alerts

Interpreting Foreign League Statistics: Sabermetrics Glossary for Fantasy Baseball (2025)

Shota Imanaga - Fantasy Baseball Rankings, Draft Sleepers, MLB News

What tools are available for foreign leagues and how to use sabermetrics for fantasy baseball? An in-depth overview of the Korean Baseball Organization (KBO) and Nippon Professional Baseball (NPB).

Welcome, RotoBallers, to our primer on interpreting foreign league statistics. This article is a deeper dive into how to interpret foreign statistics and is part of our ongoing series "Using Sabermetrics for Fantasy Baseball."

In this article, we'll focus on statistics from the Korean Baseball Organization (KBO) and Japan's Nippon Professional Baseball (NPB). Imports from both leagues generate a lot of hype and fantasy interest, and this article will help you establish reasonable expectations for them.

You can find our entire sabermetrics glossary, which includes links to many other sabermetric stats, as part of this series. Good luck in 2025!

Be sure to check all of our fantasy baseball lineup tools and resources:

 

Interpreting Foreign Statistics: Sabermetrics Glossary

Major leaguers are on every fantasy manager's radar, and minor leaguers are as well. However, there's still one player pool that you might not be familiar with.

There are international leagues outside of MLB, with imports making a huge impact for real-life MLB clubs and fantasy gamers. Kodai Senga finished second in Cy Young voting in 2023. Shota Imanaga won fantasy leagues last year. Yoshinobu Yamamoto was elite on a per-inning basis in 2024.

Of course, not every import is a home run. The Red Sox tried to trade Masataka Yoshida with no takers. Jung Hoo Lee wasn't lighting the baseball world on fire before an injury prematurely ended his debut season.

Fortunately, fantasy managers have the tools to determine what to expect from these imports. Let's learn how to use them!

 

A Primer on the Korean Baseball Organization (KBO)

The KBO is famous for epic bat flips and for being the first professional sports league to resume play following the COVID-19 pandemic. Conventional wisdom says that the caliber of play is roughly Double-A, but that overestimates the league's current capabilities.

By Double-A, most pitchers either have good stuff but struggle with command or decent command of subpar stuff. KBO pitchers averaged 89.1 mph on the radar gun in 2023, roughly five ticks below the MLB average. For every 92 mph fastball, someone is topping out at 86.

Command is harder to quantify, but this author watched KBO games on ESPN during the pandemic and Korea's early morning games during the 2023 World Baseball Classic. Command and control were lacking in these eyes, even for the KBO All-Star team in the WBC.

The KBO's statistics last season suggest nothing's changed. The league hit .277/.352/.420 with a 9 percent BB% and 19 percent K%. The Kia Tigers were the league's runaway champions and led the league with a 4.40 ERA. All 10 teams allowed more than five runs per game.

The lack of pitching means KBO hitters don't face anything resembling big league pitching until they leave Korea, generally facing a lengthy adjustment period. Jung Hoo Lee hit .262/.310/.331 with two homers in 158 PA before an injury derailed his season.

Ha-Seong Kim struggled mightily in his first big league season, slashing a putrid .202/.270/.352 with eight homers and six steals in 298 PA back in 2021. He didn't become a fantasy option until two years later.

Hyeseong Kim couldn't land an MLB job this offseason after hitting .326/.383/.458 with 11 HR and 30 SB in the KBO last season. The Dodgers are a difficult roster to crack, but he presumably would've chosen an MLB role somewhere else if one was offered.

Long-term projects make sense for MLB teams, but fantasy managers should fade KBO imports, considering the expected adjustment period. It's just too big a jump in opposition to expect immediate success.

 

Projecting Imports from Nippon Professional Baseball (NPB)

Conventional wisdom says the NPB is roughly equivalent to Triple-A, but that underestimates the league. The replacement level is lower than MLB since the league pulls from a smaller player pool, but top-line Japanese players are all MLB-caliber.

Interest in NBP is also extremely high, meaning tools have been developed that are comparable to Baseball Savant. The NPB Pitch Profiler developed by bouno05 is one of the coolest. It has a bare-bones interface, but that just makes it easier to use.

You can ignore most of the boxes. It defaults to last year, but you can toggle to any year since 2020 for more data. When you have the right year, scroll down to "Select or Input a Player" and type in the name you want to look up.

Note that it uses phonetic English spellings, meaning Roki Sasaki isn't in the database, but "Rohki Sasaki" is. Luckily, it is smart enough to give you the name you want most of the time. Click "Generate!" to see a wealth of information.

We'll use Shota Imanaga's 2023 season as an example to see if we can predict his MLB performance with the benefit of hindsight. The default view looks like this:

That's a lot, but we have platoon splits, K%, BB%, GB%, HR/FB, and even SIERA. NPB's league averages are included for context, and the numbers represent percentiles just like Baseball Savant.

Imanaga was in the 99th percentile for K% and 81st for BB%, meaning he dominated in the first two things fantasy managers look at. His MLB marks last year were 25.1 percent K% and 4.0 percent BB%, so the raw Japanese stats were a decent MLB projection.

We also see that Imanaga's GB% was low at 35.3 percent. His MLB mark was 37.2 percent, so again, the raw number was a reasonable projection.

However, we haven't seen the best stuff yet. Click "Pitch Arsenal" below the "Generate!" tab for granular data on every pitch Imanaga threw.

This is Pitch Info. We have SwStr%, GB%, IFFB%, Stuff+, and Location+ among other things. Let's focus on SwStr% and compare his 2023 arsenal to his 2024 Pitch Info data.

The NPB Pitch Tracker classified Imanaga's splitter as a change, and its SwStr% increased at the MLB level. The same is true of his slider and sinker, while his fastball remained respectable against MLB batters. If anything, Imanaga may have deserved more strikeouts than he generated in his rookie season since his SwStr% increased.

We can infer additional information from these statistics, too. Imanaga's fastball combined a low 25 percent GB% with a 17.3 percent IFFB% and elite 125 Stuff+, suggesting a high-spin offering. Sure enough, Imanaga averaged 2,442 RPM on his fastball with 98.8 percent Active Spin last season. He only averaged 91.7 mph on the radar gun, but his fastball had the late life necessary to succeed.

Imanaga's NPB data had a direct correlation with his MLB performance. This will help us project Sasaki, Tomoyuki Sugano, and anyone else who comes over from Japan.

Bouno05 developed an NPB Bat Profiler, too, and the interface is the same. There hasn't been a high-impact Japanese bat in a while, but 3B Munetaka Murakami is expected to be posted after the 2025 season. Here is a preview:

He strikes out too much and hits enough fly balls to hurt his BABIP, but we're looking at big power here. The 25-year-old is also more than willing to take a walk. The downside is probably Rhys Hoskins, with the upside looking like prime Pete Alonso.

 

Conclusion

Fantasy managers might not be familiar with the tools to evaluate foreign players, but they're out there and will only become more important as more players jump to MLB. Learning them now could give you a competitive advantage for years to come.



Download Our Free News & Alerts Mobile App

Like what you see? Download our updated fantasy baseball app for iPhone and Android with 24x7 player news, injury alerts, sleepers, prospects & more. All free!



More Sabermetrics & Statcast for Fantasy Baseball




POPULAR FANTASY TOOLS

Expert Advice
Articles & Tools
Import Your Leagues
Daily Stats & Leaders
All Pitcher Matchups
Compare Any Players
Compare Any Players
Rookies & Call-Ups
24x7 News and Alerts

REAL-TIME FANTASY NEWS

DJ Moore

Bears Experimenting with DJ Moore in Backfield
Rome Odunze

Could Move All Around the Offense
NFL

Dave Canales Comfortable With Panthers' Young Receivers
Quinshon Judkins

Not Considering NCAA Return
Dallas Goedert

Healthy for Week 1
Marvin Mims Jr.

Returns to Practice Monday
Lourdes Gurriel Jr.

Carted Off Monday With Knee Injury
Jason Adam

Diagnosed With Ruptured Left Quadriceps Tendon
Victor Wembanyama

Looking "Quite Stellar"
Fernando Tatis Jr.

Scratched on Monday
Matthew Stafford

Expected to Start in Week 1
Edward Cabrera

Heading to Injured List With Elbow Sprain
Najee Harris

Cleared for Contact, Could Play in Week 1
Denny Hamlin

Ends Eventful Day at Darlington in Seventh Place
NASCAR

Bubba Wallace Almost Earns a Top-Five Finish at Darlington
John Hunter Nemechek

has His Best 2025 Performance at Darlington
Ryan Blaney

Has An Underwhelming Performance At Darlington
Josh Berry

Crashes Early and Suffers A Playoff Setback at Darlington
Harry Ford

Called Up for Major-League Debut
Victor Scott II

Activated From Injured List
Fernando Tatis Jr.

Dealing With Hamstring Tightness, Expects to Play Monday
Giannis Antetokounmpo

"Staying in Milwaukee"
Thanasis Antetokounmpo

Agrees to a One-Year Contract with Milwaukee
Kyrie Irving

"Healing Up Great"
Dante Exum

Mavs Agree on a One-Year Deal
Jaylen Warren

Agrees to Two-Year Extension With Steelers
De'Von Achane

Practicing Monday, on Track to Play in Week 1
Quinshon Judkins

Could Report to Browns This Week
Kansas City Chiefs

Chiefs, Trent McDuffie Not Expected to Finalize Extension
Chase Elliott

Under Playoff Pressure After 17th-Place Darlington Finish
Kyle Larson

Despite Hendrick Mediocrity, Kyle Larson Remains Pretty Safe in Playoffs
Alex Bowman

Opening-Lap Crash and Botched Pit Stop May Have Sunk Alex Bowman's Playoff Hopes
Erik Jones

Darlington Master Erik Jones Comes Up Short but Still Finishes Third
AJ Allmendinger

A.J. Allmendinger Impresses at Southern 500
Dameon Pierce

Ahead of Schedule, Ready for Season
Jordan Love

May Wear Thumb Brace During Season
Chicago Bears

Bears Head Coach Admits Offense Could Face Learning Curve
Matt Chapman

Leaves Early on Sunday, Expects to Play Monday
A.J. Brown

Says He'll Be Active For Season Opener
Luis Garcia

to Make Season Debut on Monday
Max Scherzer

Exits Due to Back Tightness
Taylor Ward

Exits Early After Collison
Braelon Allen

Says He Has a Lot Left to Prove
Sal Stewart

Reds Promoting Sal Stewart to Majors
Daniel Suarez

is A DFS Risk for Darlington Lineups?
Randy Rodríguez

Randy Rodriguez to Undergo Tommy John Surgery
Noah Gragson

Should Fantasy Managers Roster Noah Gragson for Darlington?
Ty Dillon

is an Excellent Punt Option for Darlington DFS Lineups
Bogdan Bogdanović

Bogdan Bogdanovic to Miss the Rest of EuroBasket
Denny Hamlin

Picking Up Where He Left Off At Darlington
Kyle Larson

The Sky Is The Limit for Kyle Larson at Darlington
Ryan Blaney

a Strong DFS Play at Darlington This Weekend
Tyler Reddick

Shouldn't Be Overlooked at Darlington This Weekend
Alex Bowman

An Easy Place-Differential Play in DFS This Weekend
Ty Gibbs

Could Be Strong at Darlington This Weekend
Erik Jones

Has Best Darlington Qualifying Effort Since Last Win
Zane Smith

Hopeful For Another Solid Run At Darlington
Aroldis Chapman

Agrees to Contract Extension
Juan Soto

Homers Twice in Loss
Nick Kurtz

Avoids Serious Injury
MacKenzie Gore

Placed on 15-Day Injured List
Jazz Chisholm Jr.

Reaches 25-Homer, 25-Steal Milestone
Chris Sale

Activated on Saturday
Dansby Swanson

Homers Twice, Drives in Six in Win
Nick Kurtz

Leaves Game With Oblique Soreness
Joe Burrow

Bengals Feel Joe Burrow Just had "the Best Training Camp of his Career"
Dallas Mavericks

Olivier-Maxence Prosper Waived by the Mavs
Lauri Markkanen

Dominant in Win Over Great Britain
Nikola Jović

Nikola Jovic Leads Serbia to a Win
Nikola Jokić

Nikola Jokic Shines Versus Portugal
De'Von Achane

Should be Ready for Week 1
Jose Alvarado

"Good" After Recent Fall
Green Bay Packers

Packers Acquire Micah Parsons, Sign him to Four-Year Extension
Jauan Jennings

Remains Sidelined at Practice
Lauri Markkanen

Torches Sweden
Neemias Queta

Dominates in EuroBasket Opener
Kawhi Leonard

Clippers Not Allowing Kawhi Leonard to Play Back-to-Backs
Dallas Mavericks

Mavericks Looking to Trade Olivier-Maxence Prosper
Tyrese Haliburton

Expects to Return in 15 Months
Terance Mann

Confident About Having a Big Year in Brooklyn
Zaccharie Risacher

Aims to Improve Ball-Handling Skills
NBA

Pistons And Timberwolves Join Race for Malik Beasley
John Tonje

Signs Two-Way Deal With Jazz
Max Strus

to Miss 3-4 Months After Surgery

RANKINGS

QB
RB
WR
TE
K
DEF
RANKINGS
C
1B
2B
3B
SS
OF
SP
RP