you can start hanging out in the website and start watching the high rollers tab to see how most of them make bets, and it is sometimes exiting to see that much bitcoin in one bet in a high roll
but from what i have seen it is usually not martingale they use. they mostly use low multipliers with high chance of win and make bets that way.
What kind of strategy use big amount to had a high chance of winning? Sometimes i incounter 6 straight lose in bitslers i don't know what is the reason of this if you're going to ask people how much v.i.p player bitcoin gets from bitsler? wagered are important for me i don't play just for profit im there to make fun also with my few friends.
i am not exactly sure if you are asking a question with the question marks and not sure what the questions is!
the strategy as i said is different with each one and they each use different strategies, i am not exactly following them to know every single move
for example (from current history) there is someone making 4.5 LTC bets with a 1.1x multiplier (90% chance of win) and there is another one making 13 LTC bets with 1.0103x multiplier (97.99%) and so on.
and as for the reason of your loss, it is because bets are independent from each other. if you have lost the last bet it doesn't mean you should win this one or vice versa. each bet is completely random and on its own.