A word of advice on judging an unpublished writer’s contest. If you receive an entry with so many mistakes you know the person is a newbie, point out the top five-ten areas of improvements. If you were to try to correct everything, the writer will shut down about halfway through reading it and ignore the whole critique, believing the judge was being over critical. So by concentrating on the most important aspects, you get your helpful advice across to the entrant and you don’t waste your time.
Oh, another thing. My writers' group contest has the maximum score at 100 points. I can tell you, anyone with a 90 or less on more than one entry, rarely finals, and never in the big three categories (Romantic Suspense, Single Title and Unique Genres). So personally I seldom give anyone a score below a 70. To me, no matter how bad the entry is, giving a small score is senseless and demoralizing to the entrant. The person is going to ignore your critique (see paragraph above). So critique kindly and be generous within reason on your scoring. Like I said, they won’t final anyway. Just my personal opinion.