They only release so many rooms for each date for the AP rate. If the Poly has a high occupancy rate for your dates, they may not release an AP rate. You can also ask them if they have AP rates for individual dates, you maybe able to split your reservation, part AP & part regular.
Booking in advance guarantees that you will have a room. If you absolutely will not pay regular rate, then wait for AP rates to come out. I got stung by waiting last October. I wanted to stay at BWI but didn't want to pay full price so I waited. I bought plane tickets for Oct 1 to 6 thinking Oct 1 was the last day of value season and I would get a better rate. Oct 1 ended up selling out totally at BWI before AP rates came out due to a convention. Actually no AP rates came out for Aug 24 to Oct 1. If I would have booked it, I could have paid regular price for Oct 1 and then got an AP rate for Oct 2 to 6. We ended up staying at CBR, I did not want to move on a short trip.
