  Sports league scheduling is a difficult task in the general case. In this
short note, we report two improvements to an existing enumerative search
algorithm for a NP-hard sports league scheduling problem known as "prob026" in
CSPLib. These improvements are based on additional rules to constraint and
accelerate the enumeration process. The proposed approach is able to find a
solution (schedule) for all prob026 instances for a number T of teams ranging
from 12 to 70, including several T values for which a solution is reported for
the first time.
