Three games into the 2018 CPBL season, fans in Taiwan are starting to notice the strike zone is slightly taller this year. While the league have confirmed the strike zone expansion, it is still unknown whether this new strike zone is part of the league strategy to increase the pace of play.

CPBL old strike zone vs 2018 strike zone comparison. Left is old strike zone, right is 2018 strike zone.

Testing the New Strike Zone Since November 2017

Since the CPBL winter league (Asia Winter Baseball League) back in November last year, many CPBL fans have noticed there is something different about the strike zone, the CPBL umpires are starting to pick up the “top 1-2-3” spot of the strike zone.

At first, many people suspect maybe this only applied to the Winter League, as there are teams from Japan, Korea, EU and USA participating, that the league was trying to make the strike zone more “international friendly”.

But after seeing the umpires are still calling the top 1-2-3 spot of the strike zone during the CPBL spring training games, it seems the league is really going going for the strike zone expansion.

Official Statement from CPBL Umpire Chief

We have adjusted the strike zone for the 2018 season, and have informed the teams during spring training,” said CPBL Umpire Chief 蘇建文 (Su Jian-Wen).

The CPBL umpire chief also told the media that the league have decided to expand the 2018 strike zone vertically by one baseball in the “top 1-2-3” spot of the strike zone. But the horizontal will remain the same.

2018 cpbl adjusted strike zone
2018 CPBL strike zone expansion, now one ball higher. Umpires start picking up the top 1-2-3 spots.

Increase the Pace of Time?

Since we are only three games into the season, it is still too early to tell whether the decision to expand the strike zone will increase the pace of play. But the limited early data suggest, that is the case.

  • 2017 Average Game Time (240 Games) – 3 hours 28 minutes.
  • 2018 Average Game Time (3 Games) – 2 hours 57 minutes.

What Players and Coaches Think

Apart from the vertical strike zone expansion this year, the players felt that the league have expanded the strike zone horizontally as well. As several players have mentioned the horizontal expansion when talking to the media.

周思齊 (Chou Szu-Chi): It is still too early to tell, as the umpire from the game was known to have a slightly wider strike zone then the rest of the umpire in the CPBL.

藍寅倫 (Lan Yin-Lun): Going to be a lot tougher for us hitter to hit with the horizontal expansion.

洪一中 (Hung Yi-Chung): I always told our players, that they should adjust to the umpire’s strike zone not the other way around.

陳禹勳 (Chen Yu-Hsun): Most of the professional league in the world have the strike zone in a rectangular shape, but for the past few seasons in the CPBL it is in a shape of a square. The new 2018 strike zone is how a normal strike zone should looks like.


  1. A taller strike zone, if the umpires call high strikes consistently, will favor fastball pitchers. CPBL teams will start looking for foreign pitchers with faster fastballs if more high strikes are called.

    • Back to a normal strike zone now. They shrink it down and sort of removed 1-2-3 spot between 2015 to 2017. People in Taiwan are calling it the A4 strike zone.

      I’ll update this blog post the next few days, and will add more info about a few strike zones from the previous seasons. I want to do a bit more research and get some video clips first.


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