the dropchance equation is not off. The chances under info are the chances of a block of that spawning on a given level. we can't actually see the dropchance equation.
for all of you at the "new I see...welcome" screen, its best to just say yes to the continue screen, it still starts you a the beginning of the game and you can figure out how to play from there.
 "Realm Revolutions"){kind=icon}
 "Realm Grinder"){kind=icon}
 "Five amigos IDLE"){kind=icon}
 "Survival Idle"){kind=icon}
 "Idle Mine"){kind=icon}