Saxon genitive to identify algorithms, methods, techniques, theorems,
I think apostrophe+s is always preferred. I tried googling and checking various algorithms in Wikipedia, and most of them use the saxon genitive, because they simply belong to the person. Even the Newton-Raphson one is also known as Newton's method.
I can't really explain why this inconsistency exists, but checking a few names in NGrams, I'd say that "'s" is always preferred, since there's a big difference in results of the two forms.