Key indicator for winning soccer matches: net efficiency

Current soccer match analysis focuses predominantly on team tactics and technical aspects, such as offensive and defensive strategies and their transitions. However, match efficiency has received limited attention, making it difficult to explain scenarios where a team dominates possession but fails to secure victory. This study introduced the concept of soccer match efficiency and proposed computational formulas for offensive efficiency (OE), defensive efficiency (DE), and net efficiency (NE). Using data from the Chinese Super League (CSL) between 2014 and 2019, we analyzed NE as a metric for evaluating the balance between a team’s offensive and defensive performance. Net efficiency effectively reflected the balance between offensive and defensive performance and elucidated the phenomenon of “dominating possession but failing to score.” In the CSL: (1) an NE ≥ 0.2 corresponded to an 80.62% win probability; (2) an NE between 0.1 and < 0.2, 64.38%; (3) an NE between 0 and 0.1, 46.07%; (4) an NE of 0, 0%; (5) an NE between − 0.1 and 0, 24.69%; (6) an NE between − 0.2 and − 0.1, 11.25%; and (7) an NE ≤ -0.2, 5.38%. (1) Net efficiency showed a clear positive association with match outcomes, with higher NE values corresponding to higher winning rates. (2) Net efficiency provided a quantitative measure of offensive-defensive balance and offered a clearer explanation for why teams may dominate possession yet lose.