Ten-pin bowling ball contacts only the 1, 3, 5 and 9 pins; for a left-hander, the 1, 2, 5 and 8 pins. In order to count, a pin must be knocked over entirely. If the pin is wobbling as the automatic pin machine picks it up (or the machine itself knocks over the pin while it is wobbling), it is still considered standing and is not scored. Also, if a pin is moved, it does not change its designation. For example, if the 10 pin were still standing and the 7 pin slid into the 8 pin position, converting this spare would
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