There was one certain time around 2021 when some sports prediction codes were shared among gamblers, but after the game, there were a lot of winnings, and the betting site cancelled the game due to the many winnings. As of then, I knew of a guy who won about $17k; I can't remember how much he staked then, but the game was cancelled.
Not sure what type of game are you referring to, but ususally when the game is cancelled then there are no winners or losers. If the bet was won and casino decided not to pay out the winnings - then it was nothing but a fraud.
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30% is what I can afford to lose, but had the roll been repetitive, I would just split BTC0.25 into 5 places and play it 5 times.
VERY bad idea. If you have a mathematical edge over casino, for the repetitive bets, the best tactic is to play with minimum bet increments to reduce the risk of going bust in case of a long losing streak.
Statistically, you'd only win one in six rolls, so losing streak of 5, or even 10 or 15 is very likely to happen. If I recall correctly the longest losing streak recorded on JustDice was over 30 with the odds of 50%.
... In such a case betting more than you can easily afford to lose is not a wise move.
Betting 100% of all you CAN afford to lose is probably not a wise move, given the 83% chance of a loss. I mean depending on how you define the amount you can afford to lose, I guess. Could mean a different thing to different people.