Ten-pin bowling back row, then three, then two, and finally one in the front at the center of the lane. To ease communication, pins are numbered one through ten, starting with "head pin" in front, and ending with ten in the back to the right. Because of the spacing of the pins and the size of the ball (about in diameter), it is impossible for the ball to contact all pins. Therefore, a tactical shot is required, which would result in a chain reaction of pin hitting pin in a process called "pin scatter". In an ideal shot for a right-hander, the
Ten-pin bowling set by human pinsetters or "pin boys", but with the invention of the semi-automatic pinspotter in 1936 (usually just the "spotting table" component), the process became much easier. In 1946 AMF Bowling launched the first commercial fully automatic pinspotter, the AMF Model 82-10, followed closely by the more developed 82–30 model (still in common use in the 21st century) to replace the earlier Brunswick semi-automatic and fully manual bowling establishments. Brunswick itself introduced its own "Model A" automatic pinspotter design to bowling centers in 1955, and along with its successors (A2 and "JetBack", both with quicker delivery of returned balls