so to go threw all the possibilities is close to impossible.
but if he hold a reasonable hand like suited connectors, two high cards and so on and the push of the shorty gives you 2:1 or better you just have to think about calling.
if this doesnt brake your chipstack, or your tournament status, you have to make the calls with good odds.
with 2:1 odds and a hand like 89o you have to call a smalstack.
because against his range you are better then the 33% you need.
the 2:1 rule is somehow very accurate, because against a smallstack who is desperate you should have a wide shoving range.
and therefore, if you get 2:1 pott odds you might call with a hand weaker then avarage.
suppose you hold 28o in the big blind and your getting 2,5:1 odds because a small stack pushes all in. then the following acours:
if he pushes 33% of his hands youhave 30% equity against this range. so your call is a good call based on pott odds.
because in the long run this call EARNS you some chips
of course there are situations where calling would be a mistake, but the 2:1 rule is really good to deside if you call or not.
with better then 2:1 odds iam willing to call (if this ends the hand) with any two cards because againstthe all in range im doing good with calling.