Other variables go into it, such as fastpasses, etc. For instance, if I score that elusive FOP fp at the same time I have Yak and Yeti, then Yak and Yeti is gone.
I'm with you on the lack of reservations available. In fact, I've had 2 active searches in and have not had a hit on either, until I finally decided to drop the one I had yesterday. It just wouldn't work for me. A minute later, I got a message from TP informing me of a reservation available at the restaurant, lol.
I have been driving myself crazy, checking over and over, all day long for what I need. I really only have 3 reservations out of our whole trip that work for me. So, I spent last night and this morning "pretending" I was at Disney World, and where did I want to eat tonight, tomorrow, I went 3 days out, then a week, then 10 days. Every single reservation I've been looking for is available as people drop at the last minute. Try 60 days out, too. You will get what you're looking for, it'll just take time. So, I went in and dropped every reservation I have been holding on to "in case" I didn't get another. Most of my reservations were split - party of 2 and 4 respectively (we are a party of 6), 5 to 10 minutes apart. I had one an hour and a half later than I wanted. All gone. I feel so much better now, and I've only checked once today. I might just wait until closer in and keep checking for next day and 2 days out to see what pops up. Even 8 am BOG. It will all work out so I'm not stressing over it any more.