Can someone explain "walking"?
Its creating a reservation before the time you actually want to go and then you "walk" the reservation to the time you actually want to go by continuously modifying the reservation to drop days at the beginning of the reservation and adding them to the end the reservation.
Example with the 11-month window: BWV standard view studios are very often impossible to get even at 11-months out for time in October (they can fill within nanoseconds after the 11 month window opens at 8 a.m. Eastern for online reservations). They are difficult even in summer but at times in Aug or even sometime sin Sep, you will find that you can reserve them right at 8 a.m. at 11-months out. So, for example, you reserve Aug 15-22 at 11 months out but really want Oct 15-22. At 11 months out from Aug 21, you modify the reservation to Aug 21-28. At 11-months out from Aug 27, you modify the reservation to Aug 27-Sep 3, and you continue doing that type of modification every 6th day until you have the Oct 15-22 reservation.
Why does doing that work? Once you have reserved a room at 11-months out, no one else can possibly reserve that same room for any future time at all until 11 months out from the designated departure date in your reservation.
Why it usually does not work when trying to reserve at 7-months out? No matter what dates are initially reserved, any owner of the resort will still be able to reserve the same room for any time beginning after your reservation.
That does not necessarily always rule out using it for a 7-month out reservation. What it does likely rule out is getting any reservation for any class of room that usually disappears well before 7 months out, such as the BWV standard studio. Moreover, attempting any "long" walk, like over a two month period, has a very high chance of failure. But there are times and for rooms that it can sometimes work. An example is July 4 time. Often you will find BLT lake view or BWV pool/garden view rooms open when checking time for last week of June and through July 5 at 7 months out from the last week of June. If you start a reservation with a June 25 start date at 7 months out, you can possibly walk it to the getting all of the first week of July. However, if you wait until until 7 months out from July 1 to make the reservation, you ar likely to find that at least July 3 and 4 are already gone.