We often note how some pilots incorrectly fly directly over the crest
of a mountain, rather than above the steeper slope which may be well
in front, and lower than the crest. The wind goes up the slope, level
over the crest, then down the back side.

There are many places where the top of a mountain is well back behind
the lower, steeper part of the ridge. Being low and slow over the
crest may place the pilot at considerable risk if it is not possibe to
glide upwind to the steeper slope.

The book, "Ridge Soaring The Bald Eagle Ridge" explains this.

Tom Knauff