Strong factors opposing, as in There are two strikes against her possibility of a promotion. This term comes from baseball, where a batter is allowed three strikes at a fairly pitched ball before being called out; thus, a batter with two strikes has but one more chance to hit a fair ball. The figurative use dates from the early 1900s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.