What is the probability of getting KOT id? I'm glad you asked.
4chan IDs use base64 numbers, using both letter cases plus the characters + and /. To spell "KOT" using these base64 digits, we have multiple options for each letter:
>kK
>oO0
>tT7+
There are a total of 2 * 3 * 4 = 24 strings that would represent KOT. Now, we must ask how many ways we can get this substring from an ID. Since there are 8 characters in each ID and KOT is 3 letters long, there are 6 possible positions for KOT. This brings the number of KOTs up to 144. Any time we get a KOT, there are also 5 characters in the string which will be ignored, which can be any of 64 different characters. Factoring this in, there are a total of 64 ^ 5 * 144 unique KOT ids, which equals roughly 154618822656. Wow, that's a lot of KOT ids! It must not be that hard to get KOT id, right?
Well, let's look at how many IDs there are in total, KOT or not. That's 64 ^ 8, or 281474976710656. Since IDs are generated from a pseudorandom hash function, there is an approximately even distribution of IDs across posts from unique posters per thread. We can determine the odds of our id being KOT by dividing the two large numbers we have found: 154618822656 / 281474976710656 = 0.00054931640625. That means the probability of KOT id is approximately 0.05493%. In other words, if you made posted in 1820 unique threads, you would have an expected outcome of one KOT id.
