Also known as back spin , a type of spin applied to the cue ball by hitting it below its equator , causing it to spin backwards even as it slides forward on the cloth . Back spin slows the cue ball down, reduces its travel, and narrows both the carom angle after contact with an object ball , and angle of reflection off a cushion . There are several variant terms for this, including "bottom" and "bottom spin " in the US and "screw" in the UK. Draw is thought to be the first spin technique understood by billiards players prior to the introduction of leather tips, and was in use by the 1790s. See illustration at spin .