Hawgnman; you're correct that white oaks fertilize and set acorns the same year while red oaks mature their acorns the year after fertilization. Red oaks still have a crop every two years, it just takes two years for their nuts to form. On top of that cycle there is a bearing cycle. Most trees only have a high yielding year every second or third year.

Dan O.

I've attached a link which partly explains biennial bearing in apples.

http://www.hortwatch.com/library/biennial-bearing.html