Technique

Thank you very much. As you were replying me, I was playing table tennis. My friend gave me a topspin/no spin ball(those kind of balls you give for warm ups in competitions like forehand to forehand rally). And I managed to give a spinny, low topspin, penetrating back that crossed the net...and i somehow got it just by chance.(i never done that before). However, after trying several times, my old kind of return came back again- which has high( neck height), slow but spinny..Do you know why? Because I din expect to do it and it was only one time. Many thanks.