1
general::
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.
American Heritage Idioms
2
general::
Phrase(s): *two strikes against one
1. two strikes on a baseball batter, three being the number that will put the batter "out." (Such a player is in a vulnerable position. *Typically: get ~; have ~.) • Sammy has two strikes against him and might just strike out. 2. Fig. a critical number of things against one; a position wherein success is unlikely or where the success of the next move is crucial. (Fig. on Q. *Typically: get ~; have ~.) • Poor Bob had two strikes against him when he tried to explain where he was last night. • I can’t win. I’ve got two strikes against me before I start.
McGrawhill's American Idioms And Phrasal Verbs