The Chapwood index looks a bit weird. It's based on only 500 items (compare to CPI which uses 94,000 according to [1]). And those 500 items[2] include things like "cat grooming", "horseback riding lessons" and "first class airfare" (but not economy class airfare?). Tennis is apparently very important because there's "tennis lessons", "tennis racquet" and "tennis ball" in there separately. Something similar is going on for golf: we find "golf shoe", "round of golf" and "golf lessons". I could not find information on how these items are weighted.
[1] https://www.bls.gov/opub/hom/cpi/pdf/cpi.pdf
[2] https://chapwoodindex.com/chapwood-index-items/