A ten-pin bowling rack with a bowling ball impacting the head pin while the ball is centered on "board 17.5", which is believed to be the impact point providing the greatest likelihood of striking. Diagram demonstrates that, contrary to common belief, the ideal "pocket" is <i>not</i> "between" the 1 and 3 pins.
<p>Diagram also demonstrates how pins other than pins 1 and 5 are not set on boards that are multiples of 5.
</p><p>Beginning with Version 3, diagram also shows entry angles of 0°, 2°, 4° and 6°.
</p>
<ul><li>Technical note: Object sizes and distances are intended to be to scale, though there is some tiny round-off error due to Microsoft Powerpoint's accepting only two digits to the right of the decimal point.</li></ul><ul><li>Sourcing for measurements: <a rel="nofollow" class="external text" href="https://web.archive.org/web/20230604051348/https://bowl.com/getmedia/7b8b2ee2-cd3a-4fe1-ba31-1389d8fc9bbf/es_manual.pdf">USBC Equipment Specifications and Certifications Manual</a>. <i>bowl.com</i> (November 2022). Archived from <a rel="nofollow" class="external text" href="https://bowl.com/getmedia/7b8b2ee2-cd3a-4fe1-ba31-1389d8fc9bbf/es_manual.pdf">the original</a> on <span class="mw-formatted-date" title="2023-06-04">June 4, 2023</span>.</li></ul><ul><li><b>NOTE RE FIRST AND SUBSEQUENT VERSIONS:</b> Bowling ball is shifted from middle of Board 17 (Version 1) to the boundary between Boards 17 and 18 (Version 2) -- a half-board move to the left. Reason: there was ambiguity as to what "Board 17.5" means, so I uploaded versions for each interpretation. The <b><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130118212812/http://usbcongress.http.internapcdn.net/usbcongress/bowl/equipandspecs/pdfs/pinCarryStudy.pdf">2009 USBC Pin Carry Study</a></b> indicated peak strike likelihood at "2.5 inches offset", which indicates a point 2.5 inches right of <i>center</i> of the head pin (to the right of the center of board 20), which would imply that "Board 17.5" is actually the boundary between boards 17 and 18--as shown in the <i>second</i> version of this image. The strings on the lane in the picture on page 7 of the <b><a rel="nofollow" class="external text" href="https://web.archive.org/web/20130118212812/http://usbcongress.http.internapcdn.net/usbcongress/bowl/equipandspecs/pdfs/pinCarryStudy.pdf">2009 USBC Pin Carry Study PDF</a></b> confirm that the <i>second</i>- and subsequently-uploaded versions are correct.</li></ul>
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