I dont expect any but i think that if your playing well enough and can get round with the 1 ball then im sure most would get at least 2 in a round....
Having said that iv had a few over the last 12 months and funnily enough the golfing gods give me a big fat kick in the ass a hole or 2 later and get my head back down to a normal size after walking off with a single or double to balance out the card again.....
Same as Screwback, I don't expect any but try for one on most holes depending on the risk vs reward.
I used to be a member at Devils Dyke GC near Brighton and it has 3 par 5's in the first 4 holes. I have had very good starts as a result and have been 4 under after 4 on more than one occasion.
A lady member there once started, birdie, birdie, birdie, birdie, hole in one! Six under after 5! Nice!