Just to give an example if you gamble with minimum for too long with highest possible win odds then you will have played longer and have a higher wagered, if you gamble 5 btc all at the same time than you may either win 5 btc or lose 5 btc and end your quest for high volume. So, one is riskier with higher reward, the other is guaranteed loss but at least guaranteed better chance to have a long wagered with less risk of losing all your money. There are plenty of methods to try and test for it, not all works and in the end its all luck.
That is the trick here, some guy may try something and find a success with it whereas some other guy using the same exact strategy may end up losing a lot. I can tell you I had a great strategy and it worked for a long time but then it failed spectacularly.
I used to gamble with 10k satoshi each bet and put a 1.3x odd winning, it usually won and whenever I lost I actually x10 my bet and put 100k satoshi which meant I usually recovered and also made even more, now sometimes even that failed but I was making decent amount until one day I lost 3 times in a row and that emptied my whole bankroll. So, something that worked for me for weeks actually ended up costing me a lot with just one bad streak. Its not a great idea to use others strategy because it may not end up working out for you.
Winning a wagering contest and winning money with your gambling are two different goals, and one shouldn't mix up them. You lost your whole bankroll because you set 1000% increase on loss, and no wonder that 3 reds in a row drained your balance. But when you are trying to win a wagering contest, you shouldn't increase your bet size on loss. Basically, you accept that your profit is going to be negative, but you'll wager much bigger amount with the same balance, and will get a prize.