Bet big,win big.
That's how it works.He lost a big amount,but also won a big amount so yea hahah

My max bet was $500 on Serena Williams with low as fuck odds,and won

Would never do that again for sure.
You risked a lot man, because Serena is a player who can make you wonder at times why you backed her as your player.
My personal maximum bet in lifetime was 300$ on a single event and you might be surprised to hear that it was on over 2.00 odds. I remember match was between Fed vs Djok and I won it.