The evolution of match-play in Major League Soccer from 2018 to 2023

Major League Soccer (MLS) has experienced significant growth since its establishment 30 years ago. However, no research has investigated the on-field performance trends. Thus, the purpose of this study was to examine the evolution of MLS match-play via technical and tactical key performance indicators, and investigate the differences between teams according to league finishing position. MLS on-field performance indicators were obtained across six seasons from open-source website FBref. Mean game values were collected from 21 match performance indicators for every MLS team over six seasons. Teams were also classified according to their league finishing position at the conclusion of each season. Principal component analysis demonstrated that the first two components explained 62.1% of the total variance, representing possession and goal-scoring dimensions respectively. Team-season observations showed substantial overlap across seasons, suggesting that the underlying structure of MLS match-play remained relatively stable from 2018-2023. Despite this structural stability, several attacking and possession-related performance indicators, including goals, Expected Goals (xG), Total Shots, Shots on Target, Total Progressive Pass Distance, and Carries into the Final Third declined significantly across seasons. Sensitivity analyses confirmed the robustness of these findings. Higher finishing teams demonstrated superior attacking output and possession-related metrics compared to teams who failed to qualify for playoffs. The reduction in goal-scoring indicators may reflect an advancement in collective defending. MLS coaches and practitioners should give players adequate exposure to attacking game scenarios to enhance their goal-scoring effectiveness, which may also lead to a higher finish in the league.