Modeling Plate Discipline from the KBO to MLB

Plate discipline (BB%, K%, and BB/K) is one the biggest concerns for hitters making the transition from the KBO to MLB. Using data charted for the KBO Wizard, I explored the question of projecting plate discipline from the KBO to MLB using Swing%, Contact%, and similar approach metrics, using Kim Ha-seong and Na Sung-bum‘s player profiles to explore the question.

I presented this project and my findings at the 2021 SABR Analytics Conference on March 12th, 2021; you can view the video presentation on YouTube.

To my knowledge, this is the first such analysis to approach this problem using swing-level metrics, a departure from using KBO BB%/K% and applying a competition level adjustment as most projection systems do.

(Disclaimer: I will be joining the San Diego Padres as a Baseball Research and Development Intern this summer. The San Diego Padres signed Kim Ha-seong, who is discussed at length in this paper, to a 4-year deal this offseason. I would like to stress that data and work contained in this project is mine and is in no way representative of the San Diego Padres or their thought process surrounding Kim Ha-seong.)

Modeling-Plate-Discipline-from-the-KBO-to-MLB