There's a typo in HAKMEM #70 [1]. The item is a mate-in-3 as described, but always seemed mysteriously mundane to me. One day I happened across the book that the memo cites as the source [2] and found that there's a typo in the HAKMEM version of the problem: they put the white bishop on KB7, but it should be on KB8. The original makes for a much more interesting problem.<p>I wrote it up in a reddit post [3] with some notes [4] (most of which I've duplicated here). Be warned that the first comment there describes the solution.<p>[1] <a href="https://www.inwap.com/pdp10/hbaker/hakmem/games.html#item70" rel="nofollow">https://www.inwap.com/pdp10/hbaker/hakmem/games.html#item70</a><p>[2] Chess for Fun, Chess for Blood page 145; <a href="https://books.google.ca/books?id=y90UTQeLeeIC&pg=PA145#v=onepage&q&f=false" rel="nofollow">https://books.google.ca/books?id=y90UTQeLeeIC&pg=PA145#v=one...</a><p>[3] <a href="https://www.reddit.com/r/chess/comments/73h23o/problem_66_from_chess_for_fun_chess_for_blood_by/" rel="nofollow">https://www.reddit.com/r/chess/comments/73h23o/problem_66_fr...</a><p>[4] <a href="https://www.reddit.com/r/chess/comments/73h23o/problem_66_from_chess_for_fun_chess_for_blood_by/dnq7q19/" rel="nofollow">https://www.reddit.com/r/chess/comments/73h23o/problem_66_fr...</a>