It might be awarded for generally outstanding performance rather than a particular one. What's the award?
Below is where I got the quote from.
"I remarked that that movie’s lead, Michael Fassbender, deserved the year’s award for outstanding performance in a mediocre movie."
So, if "outstanding performance" has been used in a general sense like you said, does that mean the word "performance" works as an uncountable noun which requires no articles when referring to things in general and that's why I don't see any articles?