First of all I would like to note that Google’s counter shows the wrong data (also, the user should keep in view that it does not recognize punctuation marks, eg. the resuts on “capable to” will include “capable, to” as well). If you get the last page you will see that the amount of results is about 800 (80 pages) for each of the three cases: “capable to” -“capable of” “capable of” -“capable to” “capable for”, “Google books” gives approximatly the same result.

I suppose, to say briefly, “capable” relates to the “arrangement” of the subject, “able” - to its function.

The article differencebetween.net/langua … apability/ notes that the idea of “capability” contains limitation and future. That rises from an arrangement - an arrangement defines, that in fact restricts.

The dictionary dictionary.reference.com/browse/capable?s=t considers “capable of” an idiom. In this case, like “susceptible” in “susceptible of”, "capable’ in “capable of” probably takes a passive sense and is percepted as a certain analogue of “it is made of”, etc.

“Capable for” is probably a development of the idea of the idiomatic, “passive”, “capable of”, a certain analogue of “it is made for”. Though, I am not sure that “capable for” is a correct expression.

“Capable to” is probably just a usual use of “capable”.

Such are my notes and hypotheses.