to the best of
To the utmost extent of, especially of one's ability, knowledge, or power. For example, I'm sure he'll do it to the best of his ability, or To the best of my knowledge, they arrive tomorrow. [c. 1500]
Words nearby to the best of
to some degree,
to spare,
to speak of,
to start with,
to that effect,
to the best of,
to the bitter end,
to the bone,
to the contrary,
to the core,
to the effect that