keep it one hundred

a hundred and ten percent

A level of effort beyond what one can usually sustain; great exertion.

as best one can

In the best possible way, given one's circumstances and abilities.

as far as one knows

To the best of one's knowledge, as far as someone knows or possible information to be gathered about the topic, subject, aspect, or situation.

back to square one

Located back at the start, as after a dead end or failure.

bat five hundred

To be successful half of the time; to have a success rate of 50%.

be a hundred years too early

To be so immature and unprepared as to have no hope of achieving an accomplishment.

beat as one

To share the same feelings.

become one flesh

To join together in marriage; to develop a unifying bond as a result of marrying.