Originally Posted by DLDude

There are a couple of things to think about:

1. Vacation slide happens during the normal line building process. Coverage happens before the normal line building process. PBS cannot slide your vacation into a coverage pairings. Thus, vacation slide has no effect on coverage.

2. It is important to realize that the change is from bottom up denial to top down inclusion. With prefer off, the change is from right to left denial to left to right inclusion.

Even though the right to left has changed it has also been changed from denial to inclusion. In a way very little has changed. The important thing is the top is more important than bottom and in the case of Prefer Off, left is more important to right.

The significant difference between the two is that now PBS is able to consider a lower preference even if it was unable to honor a higher preference. Previously, PBS would have to deny all of he lower Prefer Off, Set Condition, and Avoid preferences in order to remove a higher preference that was the bottle neck. Likewise, PBS will consider a right date even if it was unable to honor a date to the left.