Boy, Doyle never got tired of variations on that ol' 'Red-Headed League' plot, did he?

Besides which there's some ugly racist stuff in this one which doesn't show Holmes or his creator in any very good light. One of the weakest links of the Canon.

Supposedly, this was a story which Doyle originally wrote for a completely different and more flamboyent character. Only when his publication demanded a new Holmes story did he change the names and turn this one in.

Makes sense. But I continue to be amazed at the crudeness of this by-all-accounts honourable, chivalrous and intelligent author's racial attitudes.
Then again, I suppose he's no better or worse than most thriller writers of the period (at least Holmes never encounters the Yellow Peril or suchlike.)

At least not in Doyle's works. But there are many, many "Holmes vs. Dr. Fu Manchu" pastichers among whom Derleth is a contributor.