wavl trees are designed to combine some of the best properties of both avl trees and red–black trees. one advantage of avl trees over red–black trees is being more balanced: they have height at most formula_1 (for a tree with data items, where formula_2 is the golden ratio), while red–black trees have larger maximum height, formula_3. if a wavl tree is created using only insertions, without deletions, then it has the same small height bound that an avl tree has. on the other hand, red–black trees have the advantage over avl trees in lesser restructuring of their trees. in avl trees, each deletion may require a logarithmic number of tree rotation operations, while red–black trees have simpler deletion operations that use only a constant number of tree rotations. wavl trees, like red–black trees, use only a constant number of tree rotations, and the constant is even better than for red–black trees.