Requests are just that. Requests.
They will TRY to accommodate them, but there are only so many ground floor/top floor/corner/etc. rooms.
As I understand it, if you are calling them in or using something like Touring Plans to make them, you should leave the ones available on the online check-in bit blank as those will override any others you have made.
If calling them in or using Touring Plans, it's best to limit the request to no more than 3 and put them in priority order (for example, when I was staying at All Star Sports, my TP request left the pre-populated field as-is and then in the comments section I explained that I'd like to request 1 - Surfs Up section; 2 - top floor; 3 - corner room - that way the assigner knew to first see if there were any rooms for my stay in Surfs Up, then if any of those were on the top floor, and then if any of those were on the corner. I ended up Surfs Up, top floor, second from the corner room). I also leave it more general than a specific room number - yes, I select one but I leave the floor/direction facing/such as line on the TP request as-is. That way the assigner has a clue why you are requesting the area you are.
But it's still just a request. I'm probably 50/50 for getting them, maybe even 40/60.