He says to me there's no reason for the big stack not to put the shorty all-in in that spot. But is there?
1-Remember when you put allin a player in late game your are risking more than getting back, because even if you win the hand most equity is split to other players not only to you according to ICM, you already are safe in the $, rest of players don´t, so when you take out the shorty what are you doing really is giving the $ to the others when they are not sure yet and with out risk for them.
2-having the shorty there it helps alot to you in the way that if all get tight because are afraid of be busted then you can steal frecuently from the other 2 players that are not the shorty, unless they wake up with a strong hand or are very loose (in wich case bubble will not last much any way) you can steal and steal and steal from the other players, wich help a lot more because when you get to last3 you could have a better stack.
Is not the regular to happen, i mean some folks will know what are you doing and still not have the guts to push back, but some will do after time.
Yesterday from 20 games i get 1 table like this, i was the big stack with around 5500, 2 others where around 2000, 1900, and the shorty with 1000 or less, blinds in 200, but non of then want to step up, not even the shorty and just avoid and fold around, manage to get up to 7000 and this 2 get down to 1500/1200 until i get Aces and cant affort to let it go when the shorty finaly push (with 500 left).
But yea, i do prefeer to keep the shorty when i am the big stack, if not have a decent hand will not call his push, still will get my chips back from the others.
When i am the medium stack will try to go to other medium stack, shorty gamble more and steal not work so you need a really strong hand to go for them.