For me, winning isn't just about withdrawing your money from an online casino it's also about having control over the money you use for gambling and over yourself. Sometimes, you might be able to withdraw your winnings, but if you end up depositing it back into another online casino because you lack control, you're not truly winning (Based on my own experience). That's why I believe you're real winner when you can control your gambling habits.
This is what some people do not consider and it is wrong. Fine, you might be successful in making a withdrawal now, but were you successful in making the withdrawal in the past deposits and wagering, and will you also be successful in making the withdrawal after subsequent withdrawal and wagering? These are part of the determining factors and not the immediate withdrawal that might give the gambler only temporary relief.
After wide thought on this, the best way to calculate this is the overall loss and gains you ever had. This is regardless of whether you withdrew it or not, if all the amount in your gambling account and withdrawals exceed all the deposits you've ever made, then you are successful in gambling. This is your true win.