The initial probability of recruiting SSR is 1.6%
When recruiting for 50 consecutive times without obtaining SSR, the probability of obtaining an SSR character card increases to 3.2%.
When recruiting for 60 consecutive times without obtaining SSR, the probability of obtaining an SSR character card increases to 4.8%.
When recruiting for 70 consecutive times without obtaining SSR, the probability of obtaining an SSR character card increases to 6.4%.
When recruiting for 79 consecutive times without obtaining SSR, the 80th draw must be an SSR character card.