Why does a diver pull his hands and legs close to his body when jumping from a diving board in a swimming pool to get more somersaults?

When a diver pulls their hands and legs close to their body during a jump, they reduce their moment of inertia, allowing them to spin faster. This is based on the conservation of angular momentum, which states that if no external torque acts on a system, its angular momentum remains constant. By tucking in their limbs, the diver can rotate more quickly and perform more somersaults before entering the water. Upon extending their limbs again, they slow their rotation before the entry.