On Wednesday, October 26, 2016 at 5:23:25 PM UTC+1, wrote:
A ridge out and back is drastically different. You know exactly where the opposite glider traffic will be as it is very obvious. You simply look right down the spine of the ridge.

"Simply"? - it can be very easy to fail to pick up a glider that is on a direct head-on collision path and being on a ridge makes that no easier - especially as the closing speeds may be very high.