Combination of different strings in the mains and in the crosses of the racquet.
The difference lies in material, dimension, construction and/or shape.
The main strings primarily determine the spin potential, the control, and the overall fell and durability of the string bed.
The cross strings are responsible for the comfort level, the power, and te outgoing angle that affects the trajectory of the ball.
The hybrid string setup allows players to combine the benefits of each individual string, bases on its placement in the mains and crosses.