Interactive Magnus effect simulator. A spinning sports ball experiences a lift force perpendicular to its velocity caused by the asymmetric pressure distribution created by spin. Topspin (clockwise) curves the ball downward for shorter range; backspin (counter-clockwise) lifts it for additional carry. The Magnus force F = Cl × (½ρv²A) acts perpendicular to the velocity vector. Compare the no-spin reference trajectory against topspin and backspin paths in real time.