the rule 'a if, but only if, b' was recently tested on the games section ... i didn't fully understand the rule, and given the time constraints i didn't have the luxury to stop and think about it, so i took a gamble and assumed that rule implied both 'if a then b' and 'if b then a' ... luckily, i guessed right but i *never* want to do this on a real LSAT

i know that 'a if, and only if, b' implies 'if a then b' as well as 'if b then a' ... so i understand this relationship ... i just don't get why 'but' in the example above has the same effect as 'and' in this example ... any insights would be helpful

here are my thoughts ... in 'a if, and only if, b' makes sense because it's both 'a if b ... if b then a' and 'a only if b ... if a then b' ... can someone break 'a if, but only if, b' down for me like that? Thanks!