It is a little less than 1/5th of his stack he has raised. I think he is going to have an easy time folding with many hands. I have seen players fold here many times. If you have seen him call all-ins before for a lot of chips then shove. I think you have more than just one way to play this hand and I do not like flatting so much. You can also re-raise another 4k or 5k which many players will call easier than a shove or they will come back over the top of you which is great. Then you shove all-in on any flop and make them pretty much committed because they have around half their stack in the pot. I see no problem at all with shoving like many people have mentioned but I think there is value in raising them another 4K as well especially in these 12/180 tourneys where you get a wide variety of players. If they are a regular I would be more inclined to shove by the way as shoving looks weaker than a regular raise to a reg.

I just shove he is less likely to fold pre than on the flop.

+1

SHOVE!, if he raises 4x the BB and with his stack and then folds it is a mistake and u then note that this player isn't stack size aware...Bing

Shove +1

Yea he might fold but like... getting into the habit of making atrociously obvious calls where your range is exactly AA-AA to anyone who puts any thought into it is not something you want to do too much. I'm a huge fan if you're in the BB and last to act, and people might think you're just making a dumb blind defense or something, but I think if you do this often at all, the EV you gain from possibly exploiting a donk in one spot might not outweigh the EV you lose when a reg gets a read on you and mucks QQ/AK when he sees you do it again. Not to mention that there's a decent chance shoving is the higher EV play regardless, which is what I would probably do anyways.