I do not understand the point to this play....
Player X in any position, on any street, (usually opens) bets all-in into a small pot (say ~5BBs) with a >50BB stack.
I see only two really options,
1) They have a strong hand or the current nuts
2) It is a bluff or semi-bluff.
For #1, I can see why you would want to protect your hand but you are putting way too much in for a risk/reward scenario. The rarity with the calls would mean it is very low EV and also taking into account the calls that bad-beat the big hand make this an overall negative EV play.
For #2, I like the strong bluff but the amount you are risking for such a small pot plus the 50/50 chance someone will call with a better hand or again a hand that ends up getting there (that should have not called) makes this again a very negative EV play.
Am I right on this or am I missing something that makes this a smart postive EV play?
Thanks.