Small-sided game constraints and soccer performance: a systematic review of pitch size, player number, and format effects

Abstract

Small-sided games, or SSGs, have become a mainstay of modern soccer coaching, yet the field is still fragmented when it comes to how task constraints translate into actual performance. This systematic review set out to synthesise the evidence on how pitch size, player number, and game format influence the physical, physiological, and technical-tactical performance of soccer players, and to pinpoint which design characteristics are most useful for development. The review followed the PRISMA 2020 framework, using a structured Boolean search of Scopus restricted to title, abstract, and keywords. The search turned up 843 records. After removing 15 duplicates, 828 records were screened, 42 full-text reports were assessed for eligibility, and 18 studies ultimately met all the inclusion criteria. Every included study was appraised with the Mixed Methods Appraisal Tool, and the findings were integrated through thematic synthesis. The evidence pointed in a fairly consistent direction: larger pitches and greater area per player amplify locomotor and physiological demand, whereas smaller formats increase technical-action density and neuromuscular load. Bout duration, player number, and rule constraints also modulated internal load and decision-making. For practitioners, the review clarifies dose-response relationships, highlights maturation and playing level as moderating factors, and lays out priorities for standardised, longitudinal, and sex-balanced research.