Let me talk about Supergirl's d1 vs Joker
I just think want you guys to understand how stupid this move is against certain characters.
Supergirl d1 is 7 f and is -4 on block. If Supergirl is mashing d1 then you need a 10f move to beat it and an 11f move to trade.
Joker's fastest mid is s2. Supergirl can low profile the first hit so it's essentially a 13-15 frame move against d1. So that's basically a block infinite.
What about Joker's d1 you say? It's got close to half the range of Supergirl's d1. Meaning SG can sit just outside your range and press d1d1d1d1d1d1 for the whole match until she feels like mixing in breath which, btw, is also safe.
If her d1 was a mid you could parry this move. It's a hard read but at least it's an option. Without that you just have to sit there and hold it.
Okay, so no, it's not a block infinite and no, Joker doesn't have to hold it.
Let's say Supergirl is mashing d1. Joker can stand outside its range and whiff punish with b1. How do I know this?
Well, Supergirl's d1 recovers in something like 15 frames. Joker's b1 starts in 9. Now I understand that this is some incredibly hard math, but if she does d1 again after whiffing a d1, Joker's b1 will interrupt.
But wait! There's more! Say she's doing repeated d1s on block. No Supergirl would ever do this but for the sake of the "block infinite" let's say she does.
Do you know what happens if you block the d1 and then b1? Would you care to guess? Why, you interrupt the second d1!!!
Isn't that just amazing?
Not only that, but his d1 will interrupt a d1 into breath!!! I'm sure that'll come in hand, by golly.
The more you know!