There is a word in Spanish, la chancha, that has a secondary definition that doesn't have an equivalent in English. The word is street jargon and translates to roughly mean "impossible luck" or "greedy luck" or "lucky pig." The closest single-word English equivalent might be "moxie" or "clutch."
But none of the above definitions do chancha justice.
It also means the slightly more melancholic feeling that, "I am happy with my life because I am a lucky bastard, but if ever my luck takes a day off--nay, a minute off--I might suddenly find my life pursuits unsatifying." Chancha is, to some degree, seen as an affliction, something to guard against, as in "me gusta suerte pero no me gusta el vacio sutil de la chancha" (I like good luck but not the subtle emptiness of chancha).
Or, "no deseo ser A-Rod, porque el tiene la chancha" (I wouldn't want to be A-Rod, because he has la chancha.")
Here is an example to illustrate how it could be used:
Man #1: Goooooaaaaaal!!! (Goal.)
Man #2: Que suerte! (You were lucky to score on that play, punk.)
Man#1: Si, yo tengo suerte. (Yes, I have luck on my side.)
Man#2: No, tu tienes chancha. (No, you have chancha.)
Man #1: No! No es verdad! (No.)
Man #2: No te preocupes. La chancha es un sombrero. (No worries, mate. La chancha is a wide-brimmed hat.)
This last response by Man #2 (the sombrero one) is a common expression which is intended to indicate that la chancha can be taken off like a hat, which is an oblique reference to the fallibility of someone who has chancha; a person's luck can change quickly.