I’m going to start off by saying first and foremost, relax seriously. This game isn’t broken, your block didn’t “refuse” to come out, and the world isn’t coming to an end. Also, anytime you use any of the above excuses mentioned (including my all-time favorite: LUCK), you seriously need to re-evaluate your own playstyle and critique your own gameplay.
With that being said, it’s quite simple really.
-This involves throwing out moves or actions that require no thought or planning to it, but can be categorized as shenanigans. In short, being random just means using moves that catch your opponent off guard once or twice (and if they don’t know any better, alot more), but won’t really work against players who know how to defend against such a shenanigan.
Using a mixup: This MIGHT involve throwing out a random move, however, it’s a mixup is not used the same way a random move is used. A mix up is just that: a mix~up. It’s used to confuse your opponent, to keep them guessing, and to hope they weren’t expecting/don’t know how to react in time to the new move.
Really, I’d say mixups have to do with mind-games, where random moves have to do with the act of surpising your opponent. You can use a random mixup effectively, but you cant effectively mixup random moves (against players who see it coming).
I.e. With Ken, you can catch people in between blockstrings by using kara Throw. Eventually, they will start to catch onto your patterns, and then you can mix it up by throwing a SRK when you might expect them to try to throw tech. This isn’t random because you know why you are doing it. On the other hand, it you simply walked up and did SRK and caught someone off guard, that’s just being random. It may work once or twice, but beyond that, unless you’re doing something with a purpose, its totally random.