[Mr. Graff]

I played with Gigabet at Step 3 a few hours ago. Here is a play I don't understand from him:

After a couple of failed steal attempts I'm the shortest stack at 580, he is at around 1200. Big blind is 30. He limps in from UTG with ATo, 3 more limpers (uncharacteristic of this table, which has been very tight so far). I have AQs on the button and raise 300. Gigabet raises to 800, the rest fold.

Can someone explain the wisdom of his move? Surely he must realize that I'm pot committed and won't fold. How can he voluntarily commit himself like this with ATo? Only second time I raise a pot, so it can't be because he read me as having exceptionally loose raising standards.

The only idea I can come up with is that he read my move as being one of desperation, that I basically had nothing and hoped to pick up 150 in chips, making my situation a bit better.

I usually play limit so perhaps there is something about this situation that can explain his action that I have missed.