It's called luck, and it's not BS. Just because there's an 88% chance of success on each attempt doesn't mean you will succeed for sure nearly 9 out of 10 times. You could still be really unlucky and hit that 12% chance of failure 100 times in a row. Statistically this is unlikely, but it certainly is possible. Take your licks and keep on trying, should you choose to do so. The numbers I have calculated in the original post of this thread just spell out the overall likelihood of your success, but aren't a guarantee. It took me around 50 medals to get my Shayd to star level 4 initially, possibly more, which is WAY worse than the 35% success rate I calculated. In the end, it's all about luck and perseverance. The more you try, the more likely you are to succeed, even with abysmally low rates of success like stars 7 to 9.