Overdefense
Term applying to combat games. When your computer-cotrolled opponent is almost impossible to hurt because they are using defense (or any method to avoid harm) at least 93% of the time. Almost certain to turn a terrific victory into a frustrating (and-if other people are present-humiliating) defeat.
I had a great run in Mortal Kombat until Johnny Cage started using overdefense and cost me everything.