Quit while you're... behind or ahead?

I used to, as a child/teen always think the saying referred to quitting while one was ahead at something. The idea being eventually we all get our bad game, rainy day etc and pushing our luck is asking for disaster.

However, having now had experience at gambling and seeing a different context for the saying even in other scenarios outside of gambling, I am seeing truth in those who would wrongly quote it as quitting when one is already behind, to avoid further problems and harsher downswings.

What I cannot seem to get to the bottom of is if it just that I was raised with the 'ahead' variant being normal or if it really is the original.

I'm pretty certain it's quit while you're ahead.

As a gambler, beuther is correct. You quit when the odds are not in your favor even if ahead and keep going even if behind, if the odds are in your favor

both sayings have merit.

quitting while you are ahead (winning or advancing) is sometimes good because being overzealous clouds judgement. but opportunity is limited and there are rare times to press on because of the victory/benefits

quitting while you are behind (losing or not advancing) is sometimes good as well, because you might be limited in resources, strength or time. but there are times to press on even if you are behind

if its a question of which saying originated first. then id argue quit while you are ahead.