Gacha pulls are streaky

I got Kelsey right away with the free 11-pull and ticket 10-pull, and thought it was a good start, but then I got Kelsey again on the 81st pull, so I decided to back off for a bit. Fortunately, I still had 41 tickets, which kept my resources at 300 pulls. With an additional 13 free pulls available, I'm hoping for a chance at Closure. Even though getting two Kelseys in under 100 pulls is a great cost reduction in terms of probability, I've decided it's irrational to chase the permanent Closure, so I'm adjusting my strategy around withdrawing. Getting 2 6-stars in 80 pulls is probably the minimum guarantee in terms of probability. On the other hand, I'll consider it significant that I pulled the limited ones more. Double rate-ups can often result in one character appearing 10 times and the other 0 times.