The ability to throw objects is important to hominid evolution and has been central to many technological innovations in human history. The conditions for optimal throwing performance, however, are in general unknown. Here we present ejection experiments of projectiles composed of a rigid and a soft layer. The optimal performance is achieved when the soft layer of the projectiles matches the acceleration dynamics of the throwing engine. Compared with a fully rigid projectile, a bilayered projectile with a small soft elastic layer can achieve a more than 300% increase in translational kinetic energy. Our study emphasizes the importance of not only designing projectiles to optimize the stability in flight, the aerodynamic profile, and the spin, but also to carefully match the mechanical impedance of the projectiles and their thrower.