Bowling ball to skid longer before reacting (hooking). Reactive cover stocks finishes include "matte" (aggressive reaction), "shiny" (longer skid distance than matte finish), "pearl" (greatest skid distance among reactive cover stocks), and "hybrid" (combination of skid distance and back end reaction). Duckpin balls weigh each, with up to three balls delivered per round (or "frame") of bowling for one bowler. The duckpin ball has a maximum diameter of , slightly larger than a candlepin ball but, like a candlepin ball, contains no finger holes. Duckpins are correspondingly shorter and lighter than their ten-pin equivalents and it is more difficult to knock them
Ten-pin bowling it is damaging the integrity of the sport. Before 1970, nearly all bowling balls had a hard rubber surface. As the coatings applied to wood lanes changed from softer lacquer to a harder urethane in the early 1970s, the first polyester balls became widely available. Subsequent changes since the early 1980s — particularly with urethane surfaced and later "reactive" resin or composite ("particle") surfaced bowling balls—have been altering the physics of how the ball rolls and strikes the pins. Coupled with synthetic lane surfaces and advanced oiling machines presenting the opportunity to lay out lane oil patterns that make targeting