Small-sided games are used to improve tactical-technical and physical performances in team sports. This study compared the physical, physiological, and tactical-technical responses during 3 versus 3 basketball small-sided games performed in full and half-court: numerical equality (3 vs. 3), numerical superiority (4 vs. 3), and with a non-scorer floater (3 vs. 3  +  1). A total of 45 U-14 and U-15 male athletes participated in the study. They were divided into three-player teams and played one 4-minute bout of each small-sided game type. Heart rate and the time spent in four acceleration zones (0.0–0.5, 0.5–1.0, 1.0–1.5, and 1.5–2.0 g) were recorded using heart rate monitors and triaxial accelerometers. Small-sided games were filmed for the analysis of tactical-technical behavior. Results showed a higher frequency of space creation without the ball, and a mean number of passes per offense in the formats 4 versus 3 and 3 versus 3  +  1, and a lower frequency of space creation with the ball dribbled in 3 versus 3  +  1 compared with 3 versus 3. Physical and physiological responses were higher in the full-court regardless of format and in numerical equality regardless of court area; only the time spent in the highest acceleration zone was higher in half-court small-sided games. We concluded that additional players increase group tactical actions and decrease physical and physiological responses in 3 versus 3 basketball small-sided games.

This study followed a cross-sectional design and aimed to compare the offensive and defensive tactical-technical actions and the physical and physiological responses between four 3vs.3 basketball small-sided games (SSGs) played on the half-court: with regular rules (3vs.3REGULAR), with defensive pressure (3vs.3DEFPRESS), with the close-shot rule (3vs.3CLOSESHOT), and with offensive numerical superiority (4vs.3). Fifty-one U-14 and U-15 male athletes participated in the study. They were divided into 3-player teams and played one 4-min bout of each SSG type. Heart rate and the time spent in four acceleration zones (0.0–0.5, 0.5–1.0, 1.0–1.5, and 1.5–2.0 g) were recorded using heart rate monitors and triaxial accelerometers. SSGs were filmed for the analysis of Space Creation Dynamics and defensive tactical-technical actions. Results showed a higher frequency of space creation without the ball and a mean number of passes per offense in the 4vs.3, with this SSG showing higher offensive performance than the 3vs.3CLOSESHOT (large effect sizes). Defensive behavior was significantly impacted by all rules: in general, 4vs.3 presented the highest frequency of closeouts, 3vs.3DEFPRESS increased the frequency of close off-ball marking and the 3vs.3CLOSESHOT increased the frequency of double-teaming, all differences presenting large effect sizes. Heart rate and the time spent in moderate and high accelerations (zones 2 and 3) were the highest with defensive pressure and the lowest with numerical superiority; heart rate and accelerations in the close-shot rule are higher than in numerical superiority but similar to the 3vs.3REGULAR. We concluded that the SSGs investigated in this study can stimulate different offensive and defensive actions and be used to develop the performance of basketball athletes.