Agree it also appears to be using a Bar Box as reference from the higher 30* angle givenPhil Capelle’s “Play Your Best Eight Ball”.
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It's not one of Byrne's diagrams. His are real close to a Gold Crown:The diagram looks like what were used in the Robert Byrne books, but I could not tell you which of them exactly. From the basic knowledge it shows about equipment I'd guess the Standard Book of Pool and Billiards.
ThanksPhil Capelle’s “Play Your Best Eight Ball”.
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