Philly defense.. efficient?

[Sandman1995]

Okay jw. if i wanted to start trying to learn how to do this if it would be efficient
Out of boxing. like mma if it would work at all, or a street fight if someone was coming at me,
or would it just not work.?
pretty much.. is the way james toney, floyd mayweather, etc how they fight, can that be used out of boxing.?
AND. how long does it take to learn decently?
(i have pretty good head movement, and pretty athletic)