In cricket, particularly in spin bowling, the terms "side spin" and "over spin" refer to the types of spin imparted on the ball by the bowler.
Side Spin: Side spin, also known as "side spin axis," refers to the rotation of the ball around a horizontal axis that is perpendicular to the direction of the ball's travel. When a spinner imparts side spin on the ball, it causes the ball to deviate sideways during its flight, either away from or towards the batsman, depending on the direction of spin. This sideways movement is commonly referred to as "turn" or "break." For example, an off-spinner will typically impart side spin on the ball, causing it to turn from the off-side to the leg-side (for a right-handed batsman).
Over Spin: Over spin, also known as "top spin," refers to the rotation of the ball around a vertical axis. When a spinner imparts over spin, the top of the ball rotates forward relative to the direction of its travel. This causes the ball to dip and bounce more sharply when it hits the pitch, making it challenging for the batsman to judge the length and height of the delivery. Over spin is commonly used by spinners to deceive batsmen and induce mistimed shots or mishits.
Both side spin and over spin are essential techniques in spin bowling and can be combined to create variations and deceive the batsman. Skilled spinners often master the art of imparting various combinations of side spin and over spin to generate different types of deliveries, such as off-spin, leg-spin, googly, doosra, and more, each with its unique characteristics and challenges for the batsman.