Okay so with all the speculations and hype for Gogeta Blue dropping probably around Christmas, I decided to do some math for how many crystals u need to have a reasonable chance to pull him.
TLDR: It’s 20,500 crystals. That gives you a 51.6% chance to get him after 5 rotations on the step-up and a 67.94% chance to get him on the guaranteed sparking assist banner.
Of course you can get really lucky with less but this is for best odds.
Here’s the math:
The equation for calculating the odds:
where p is the percentage (in decimal form) of getting LF Gogeta (usually LF units are 25% chance) and n is the number of pulls you do. For a step-up, that equates to 58 singles which you multiply by the number of rotations you do on the banner (5 in this case which gives 290 pulls).
So once u put it in a calculator, the chance of pulling him is 51.6% on the normal step-up after 5 rotations. And on the guaranteed assist banner, which you can pull on 7 times, 67.94%.
20,500 crystals is the best even number to get divide the assist tickets just right so you aren’t tempted to go back into the banner. Let me know what you think.
I got the equation from this site: https://www.reddit.com/r/DragaliaLost/comments/esxdky/calculating_gacha_rates_or_why_11pn_is_your_best/