3 Reasons the KBO’s Offense Is Decreasing

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Why the KBO Offense is Decreasing

Many bettors familiar with baseball know that the KBO has historically had a higher level of offense than the MLB.

Foreign players are a big part of the reason why there are so many home runs in the KBO per year.

The Korean Baseball Organization (KBO) first decided to allow foreign players into their league in an attempt to correct a trend.

The KBO had gradually reduced in popularity through the ‘90s.

While there would be huge crowds turning out for games in the ‘80s and early ‘90s, the following of the sport began to wane during the mid-‘90s. Some stadiums were so empty that locals could be seen riding their bikes or even hosting barbecues while the games were played.

While the popularity of the KBO was decreasing, South Korea still had a long history of baseball enthusiasm.

Baseball was brought to Korea in the 19th century by American missionaries.

Americans planted the seeds of interest in baseball which would grow into a full-blown passion and, eventually, the birth of one of the biggest professional baseball leagues in the world.

Scrimmages were played against major leaguers touring in Korea in the early 20th century. At least one Korean player played on the Japanese team that went up against an American team featuring Babe Ruth.

The Intercity Baseball Tournament helped keep the popularity of baseball alive in both South Korea and Japan throughout the 20th century. While the tournament is based in Japan, it regularly featured teams from South Korea or South Korean players.

Like KBO teams, each team in the tournament is sponsored by a company. Osaka Gas, NTT East, and Toyota Motor have sponsored the last three winners of the tournament.

The Formation of the KBO

While the tournament still goes on today, both South Korea and Japan have expanded to new baseball leagues in their respective countries.

Japan has Nippon Professional Baseball (NPB), a hugely popular league that has had many MLB superstars pass through it, and South Korea has the KBO.

Founded in 1982, the KBO has exceeded the popularity of the Intercity Baseball Tournament and was formed thanks to the continued interest in baseball by the people of South Korea.

Until 1998, KBO teams consisted of only players born in South Korea. However, as early as the end of the league’s inaugural season, the KBO had been considering changing the rules to allow foreign players to sign with KBO teams.

It was expected that the KBO would begin allowing foreign players to join the league within the first five to seven years of its existence, but it took 16 years for outsiders to be allowed in the league. On the other hand, the NPB had been signing foreign players for years.


Eventually, in 1998, thanks to pressure put on the league due to increase popularity and revenue, as well as other factors, the KBO began allowing foreign players to sign with their teams. This was a step in the right direction towards a more inclusive and popular league.

Currently, every KBO team is allowed a maximum of three foreigners, so teams are still restricted by the league and can’t just sign any foreign player they want.

Teams must choose three players who can impact their team the most, whether that’s filling a positional hole or just the three best players willing to sign with the club.

The KBO is known now as a highly offensive league, with lots of home runs being hit every game and games ending with high run totals. However, steps have been taken by the league in recent years to reduce offensive output.

While many real money gamblers may expect the league to continue boasting high runs/game, people should be wary of the changes occurring in the KBO.

Totals bets will be affected by the modifications the league has made to reduce offense.

The League Has Had Lots of Offense Historically

While many assume that the KBO has always been a high-scoring league, this isn’t the reality.

Until about 1992, the KBO and the MLB both had roughly the same runs scored/game. While individual seasons by each league may have been higher or lower, the leagues both routinely outscored each other until the 1992 season.

During the ’90s, the MLB had a huge offensive burst. At the time, this was evidenced by many home run contests, such as the famous race in 1998 where Mark McGwire battled Sammy Sosa to break Roger Maris’s home run record, which had stood since 1961.

Both McGwire and Sosa broke the record in 1998 as McGwire ended the season with 70 HRs and Sosa accumulated 64.

Now, with the benefit of hindsight, we can see that this burst in home runs was caused by the popularity of steroids among MLB players.

Like the ‘80s, the ‘00s consisted of the KBO and MLB outsourcing the other league in years at different points.

Throughout the ‘00s, there was no clear leader between the leagues as the KBO hadn’t gained the notoriety of being an offensively charged league yet.

However, in the 2010s, the offense of the KBO exploded. The league would score around 5.5 runs per game from 2014 to 2018.

Coincidentally, the MLB had a reduction in offense over this team, as steroid use was now being tested by the league and many of the MLB’s steroid users had retired.

Perhaps the combination of the KBO’s offensive increase and the MLB’s offensive decrease gave a stronger impression than what really happened.

Regardless, people caught on and many bettors began to expect the KBO to always have a high number of runs scored every year.

The league has since adjusted and taken some steps to reduce the runs scored per game, and it’s worked.

The KBO is no longer the high-scoring league it used to be. The KBO and MLB both scored roughly the same amount of runs per game in 2019.

Several factors have contributed to the reduced level of offense in the KBO.

1 – The Ball Changed Before 2019

Before the 2019 season, the KBO changed the coefficient of restitution (COR) value in their baseballs.

This value affects how far baseballs travel through the air after being struck by a bat. The higher the value is, the more fly balls will turn into home runs and the more runs will be scored per game.

Before 2019, the KBO played with baseballs with the highest COR value between the KBO, NPB, and the MLB.

Now, baseballs in the KBO have roughly the same COR value as baseballs in the NPB. Both leagues still play with higher COR value baseballs than the MLB does.


This may be the biggest reason for the KBO’s reduction in runs.
The number of runs per game took a sharp dive in the 2019 season compared to the 10 years before.

While other changes have affected the league, the KBO had the biggest immediate change the first year after the COR values were changed.

If the trend continues into this year, expect the under to be a good bet on many KBO games.

Oddsmakers may not have adjusted to the change in the ball, and many teams may continue to struggle to hit as many home runs as they used to.

2 – The Strike Zone Changed Before 2017

Before changing the baseballs, the KBO tried increasing the size of the strike zone before the 2017 season.

The wider the strike zone is, the more of an advantage pitchers have. The league hoped that the change would result in more strikeouts and fewer homers.

The effect was noticeable at the beginning of the season, but overall, the league failed to reduce the offense of most of its teams.

Umpires struggled to enforce the new strike zone and the overall numbers suggest that the runs per game were just as high in 2017 and 2018 as it was before the strike zone change.

3 – Many Hitters Have Gone to the MLB

While the league only allows three foreigners per team, many of the best offensive players in the KBO have been former MLB players.

Eric Thames hit over 40 home runs two seasons in a row in the KBO and became the third foreign-born player to win the KBO MVP award.

Like other great KBO players, Thames was scouted by an MLB team and left the KBO once his contract was up.

The revolving door-nature of the KBO means that many of its brightest stars eventually leave for MLB teams.

When great offensive players leave the league so often, the offense of the whole league can suffer.

Consider Betting Under on KBO Totals Bets

The KBO has implemented measures to reduce offense in the league since 2017, and it’s likely that the league won’t continue to be such a hotbed of home runs and runs scored.

While many expect the league to continue being an offensive force, don’t be surprised if the offense more closely resembles 2019 levels in 2020.

If it does, the under may be a good bet throughout the year, as online betting sites struggle to adjust to changes implemented by the league.


Do you think the KBO’s runs per game will bounce back? Let us know in the comments.

Michael Stevens

Michael Stevens has been researching and writing topics involving the gambling industry for well over a decade now and is considered an expert on all things casino and sports betting. Michael has been writing for GamblingSites.org since early 2016. ...

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