Travel Distance and Direction Negatively Impact Expected Goal Differential: A Retrospective Analysis of 2018–2023 National Women’s Soccer League Data

Purpose: This study investigated the impact of travel distance and direction on performance indicators in the US National Women’s Soccer League (NWSL). Methods: Data from 510 regular-season matches across the 2019, 2021, 2022, and 2023 seasons were analyzed using open-access data from StatsBombIQ. A multimodal analysis employing linear mixed-effects models was conducted to examine the relationship between travel metrics (distance and direction) and performance outcomes (expected goal differential [xGD]) while controlling for rolling win percentage, opponent rolling win percentage, and game location. Results: Teams performed best at home (xGD = 0.26). Performance declined in all away scenarios: westward travel (xGD = −0.52), neutral time-zone travel (xGD = −0.26), and eastward travel (xGD = −0.01). Pairwise comparisons confirmed a home advantage over all travel conditions: westward (Δ xGD = 0.78), neutral (Δ xGD = 0.51), and eastward (Δ xGD = 0.27). Among away games, westward travel resulted in poorer performance than both eastward (Δ xGD = −0.51) and neutral travel (Δ xGD = −0.26). Eastward travel showed better performance than neutral travel (Δ xGD = 0.25). The most pronounced difference, home versus westward travel (Δ xGD = 0.78), exceeded 0.60 xGD, a magnitude capable of shifting the likely outcome of a match. Conclusions: Travel distance and direction negatively affect performance in NWSL teams, with westward travel posing the greatest detriment. These findings underscore the need for improved scheduling and travel strategies. Future research should explore practical methods to reduce travel-related performance impairments in professional women’s soccer.