corelation with atk rating, def rating, block and evasion

[Stratovus 8]

i have a doubt about these four things, how exactly the game works when you attack a mob or a player, i mean how the game decides when a attack is blocked or evaded?

I know that the more atk rating you have you miss less often, but how does that work with the block, evasion and def rating of the target? @Wartale can you help me pls, im curious?