The most common and most likely answer to this crossword clue is the 8 letter word DECIDERS
I've seen this crossword clue in The Guardian
D
E
C
I
D
E
R
S
More clues leading to the result DECIDERS
Buddy explains!

The straight part
We know that "Final contests" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case final contests = deciders.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DECIDERS mean?
DECIDERS noun- (of a controversy, question, etc) A person, divinity, or authoritative text which decides.
- An event or action which decides the outcome of a contested matter.
- A Turing machine that halts regardless of its input.