Look at it this way.. Jack Sparrow's lucky go personality is what made him beat out those he "battled against" since we know that in the backs of our minds that none of his opponents would really want to defeat him. Vader would most likely ignore him, Dr. Evil would hire him on as a hench person only to get annoyed with his "incompetance" and his ability to escape death, and Obi Wan let him be knowing that someone as reckless and darksided as JAck Sparrow can actually be used as an instrument of the light if handled correctly (Jack Sparrow is like a drunker more chaotic version of Han Solo).