Given a set
S of
n points in
, and an integer
k such that
0k<n, we show that a geometric graph with vertex set
S, at most
n−1+k edges, maximum degree five, and dilation
O(n/(k+1)) can be computed in time
O(nlogn). For any
k, we also construct planar
n-point sets for which any geometric graph with
n−1+k edges has dilation
Ω(n/(k+1)); a slightly weaker statement holds if the points of
S are required to be in convex position.