bet on the wrong horse—(also: back the wrong horse) base one’s plans, etc. on a wrong guess about smth.:
- To count on the family farm as an important thing in the American future looks like betting on the wrong horse.
put the saddle on the wrong horse —(also: get the wrong pig by the tail) lay the blame on the wrong person:
- Blaming the teacher for the lazy student’s academic failure is putting the saddle on the wrong horse.