MMO high roller hits triple legendary drop so rare that people are struggling to even calculate the odds

gamesradar.com:

It is 10:54am on a Monday morning and I've had to do a ton of math that I am frankly not qualified for, all because of an unbelievably lucky Old School Runescape player who bagged three ultra-rare drops in a true feat of MMO RNG. 

I honestly don't know where to begin, so let's start with this tweet from OSRS diehard Bazilijus, who recently obtained three mega-rare items from Old School's clue scrolls in a single day, with the Twitch clips to back it up. 

?????????????????? 3 IN DAY 1 LOL pic.twitter.com/9UNqBg2SZXJuly 22, 2023

You may remember Bazilijus as the first player to get every single boss drop in an enormous grind after 22,000 total hours played. The point of that boss grind, and now this clue scroll grind, is to complete Old School Runescape's daunting collection log, which essentially tracks all the rare drops that you've obtained. This incredible clue scroll high roll has brought Bazilijus considerably closer to the (still far-off) finish line, and like many players, I'm struggling to calculate the odds because there are so many variables in play. 

Bazilijus managed to save up 600 of the reward caskets that you get from hard clue scrolls, with each clue taking around five minutes to complete (judging from his final run). That's approximately 50 hours of grinding, and he was going to cash in the payoff in a matter of minutes.

By his 426th casket, Bazilijus had obtained three pieces of the ultra-rare 3rd Age armor which is often seen as the pinnacle clue reward. I am a bit of a math nerd but I am not a mathematician, so I'm just going to do my best to explain why my gast is so flabbered.

There are 13 3rd Age items on the hard clue drop table, and the Old School Runescape wiki confirms that the odds of getting a