Working to one's ability, rather he or she fails or succeeds.

A person with an outwardly dominant, masculine, or aggressive personality, but who also enthusiastically takes on the submissive or "bottom" role in the bedroom.

giving your best effort is when you try your hardest.

To make ones greatest attempt

Giving all that you can in a given situation, but always failing to meet some one else's standards

good enough.

No effort at all.