Accuracy Vs. Evasion

So I'm trying to figure out (in ballista) how to floor someone's accuracy. But I don't know how that's done. I currently would have

61 Evasion from Agi (122)
111 Evasion gear
372 Skill

I added it up to 544.

Now my opponent would have--

66.7 Accuracy (89 Dex)
45 Accuracy in gear
384 Skill

495.7

Now if you throw in landing Blind that's -30 accuracy for 465.7.

Now how exactly do you calculate this? Can I throw this in the FFXI calculator and see? Cause that he'd get a 45.6% hit rate. If I do the -30 he'd have 26.6%. Idk how much evasion Yonin gives (30?) but I assume it's 30. Add that, and his accuracy is floored.

Is this math correct?


Final numbers Evasion 574? vs. 465.7 (Calculator says 447.3)

Once your eva and their acc is even and you are the same level, 75% hitrate.

From there, you need 110 additional evasion to floor him at 20%

That's about what I have... alright thanks. ^^