The phrase "a thorough mastery" is correct and usable in written English.
It can be used to describe a deep and comprehensive understanding or skill in a particular subject or area.
Example: "To excel in this field, one must achieve a thorough mastery of the fundamental concepts and techniques."
Alternatives: "a deep understanding" or "an extensive command".
Some 40% of those surveyed demonstrated a thorough mastery of the issues connected with the introduction of the new currency, an increase of 8% on the previous month.
Partly of Eskimo descent himself, and equipped with a thorough mastery of the Eskimo language, Rasmussen wintered among the most northerly tribe in the world, the Polar Eskimo of northwestern Greenland (1902 04).
Partly of Inuit descent himself and equipped with a thorough mastery of the language, Rasmussen wintered among the most northerly tribe in the world, the Polar Inuit of northwestern Greenland (1902 04).
The late 15th and early 16th centuries are mainly associated in Italy with the name of Guglielmo de Marcillat (1467 1529), a Frenchman whose works display a thorough mastery of technique.
It wasn't always clear whom Clinton was defending; because Hillary's voice in her husband's Administration was both strong and unofficial, sorting out the credit and the blame can, at times, require a thorough mastery of nineties-era minutiae.
The average grade in these courses is a B. Historically, the top 25-30% scores make up the A and A- range and indicate thorough mastery of the concepts and techniques covered in the course.
However, this tactic also has a disadvantage, for a thorough knowledge of the life cycle and thorough mastery of ways to handle a given organism in the laboratory are obviously of great importance to the researcher, and one can never know several organisms as well as one can know a single one.
Besides his thorough mastery of these woodwinds, he introduced an unprecedented range of unique expressive techniques on them.
But as he took requests written on slips of paper filled out by audience members, it became evident that familiarity is not synonymous with thorough mastery.
That, I think, is what we should start noting in Wheeldon's work, his thorough mastery of the ballet technique and his willingness, much of the time, to let the steps carry the meaning.
And that's in addition a love for the written word, copy-editing mastery and a thorough understanding of AP style!
