Quote from Jerkstore:
Once upon a time, customers had longer to exercise their options than MM's. Now, the rules of when to exercise an option are the same for every market participant. No one knows what they were assigned on until after processing on Saturday, but the notices have to be in by 4:30 central.
GOOG is always an interesting study. I am convinced that some large company forceably pins the stock when they can. This allows them to collect a large amount of decay on the pinned strike, and buy back everything at 2:55 on Friday. However, this group would be left with a large delta position as they force the stock up/down a few $$. To make up for this, the company will overbuy the pinned strike at 2:55, and exercise options to flatten out their delta position.
If you are short options on that line in GOOG you will often get assigned options that technically close OTM.
Your not alone in your thinking. If you do some Google searches there are quite a few papers that have studied the tendency of prices to be at or near a strike price dead on. Of course most strike prices are whole numbers so that could be part of it also. But it surely makes sense for someone that is near money on a large amount of naked options to want to push the stock around