Fischer Random Chess

Fischer Random Chess, also known as Chess960 is a variation of the game of chess invented by the former World Chess Champion Bobby Fischer. Fischer announced this variation on June 19, 1996, in Buenos Aires, Argentina. Fischer random chess employs the same board and pieces as classical chess, but the starting position of the pieces on the players' home ranks is randomized, following certain rules.

The random setup makes gaining an advantage through the memorization of openings impracticable; players instead must rely more on their talent and creativity over the board.

An example of Chess960 game, i played as BLACK:

+ "I don't know when, but I think we are approaching that [the end of chess] very rapidly. I think we need a change in the rules of chess. For example, I think it would be a good idea to shuffle the first row of the pieces by computer ... and this way you will get rid of all the theory. One reason that computers are strong in chess is that they have access to enormous theory [...] I think if you can turn off the computer's book, which I've done when I've played the computer, they are still rather weak, at least at the opening part of the game, so I think this would be a good improvement, and also just for humans. It is much better, I think, because chess is becoming more and more simply memorization, because the power of memorization is so tremendous in chess now. Theory is so advanced, it used to be theory to maybe 10 or 15 moves, 18 moves; now, theory is going to 30 moves, 40 moves. I think I saw one game in Informator, the Yugoslav chess publication, where they give an N [theoretical novelty] to a new move, and I recall this new move was around move 50. [...] I think it is true, we are coming to the end of the history of chess with the present rules, but I don't say we have to do away with the present rules. I mean, people can still play, but I think it's time for those who want to start playing on new rules that I think are better." — Fischer (September 1, 1992)

+ "Random chess lets me enjoy myself and get publicity for chess without having to disrupt my life for months of preparation." — Garry Kasparov, August 2018

The following adventure is one of the best Chess960 performance ever:

Artur Jakubiec vs Hikaru Nakamura
"The Mainz Attraction" (Game of the day Jul-05-2009)
Mainz Chess960 Tournament (2009) (Unorthodox), Internet Chess Club, rd 9, Jun-28
Chess variants (000) · 1-0

So after WHITE (Artur) surprisingly sacs his Rook 20.Rxe7+, BLACK (Hikaru) suddenly resigns!

Why is that so?

Are You able to find an unstoppable checkmate, in case BLACK's King takes a ROOK in this current position on the board?

p.s. Be my quests, please answer the question from above + post it in the comment area below. Your own experiences or favorite games around Chess960 are much welcome too