Ten-pin bowling Bowling Championships. Ten-pin bowling has an international ranking system, as with many professional individual sports. This ten-pin equivalent is known as the World Ranking Masters and is made of three vast tours: the European, Americas and Asian bowling tours. Other minor tournaments, although major in their respective countries, include Britain's prestigious BTBA Nationals (BTBA National Championships), the Brunswick Ballmaster Open, Brunswick Euro Challenge in Greece, ETBF European Youth Championships, the European Gold Cup and the Mediterranean Challenge Cup. The world's premier amateur event is the WB/WTBA World Championships (World Bowling) which has been running since 1954 and is now held
Ten-pin bowling if synthetic. The top of the pin shall have a uniform arc with a radius of . The USBC also has regulations governing the weight distribution of the pin from top-to-bottom. Pins are allowed one or two "voids" (holes) in the belly area (which can be viewed if the pin is cut in half from top-to-bottom). The voids are needed to balance the narrower top half of the pin with the wider bottom half. Without them, the pins would be too bottom-heavy to fall properly when struck. In addition, a standard regulation pin may lean no more than 10 degrees