Different person will define winning in different goals.

One can say they won if they have completely stop gambling.
One can say they won if they hit a jackpot or highest multipliers.
One can say they won if they're in profit.
One can say they won if they able to control themselves and being responsible during gambling.

Winning isn't everything about profit, but it could be achieve the biggest thing or you simply master it when the average are fall to addiction.