[5/10 is perfectly fine. See below.]

0/10- Your story does not exist. It is nowhere to be seen... It is completely wiped off of the face of the earth.

1/10- Doesn't make sense, no punctuation, no plausible theme.

2/10- No punctuation, somewhat of a simple plot line, not a lot of professionalism.

3/10- Basic plot line, no punctuation or capitals etc.

4/10- Basic plot line with some punctuation in the right place, characters not developed extensively.

5/10- Basic, somewhat developed plot line, established characters, good writing structure. A good story with good emotions from the start, worth reading.

6/10- Interesting plot line, good characters, writing flows somewhat. Descriptions are very good, story has a lot of effort shown by the writer and creates an atmosphere for the reader.

7/10- The writing is well developed and flows easily, the characters are well established and separate from each other with explored backgrounds and features.

8/10- Writing is good and in a current all-through tense, the writing flows with a complex and twisted plot line. The characters are recognisable, and the author can provide distinctive and thorough insights into the characters' feelings.

9/10- The story still has room for improvement. This can be anything like typos, a more interesting cover, a better description, a more varied range of characters, a better range of vocabulary, a larger range of writing techniques etc.
9/10 is mostly the highest rating possible.

10/10- The writing is groundbreaking, superb plot, stunning characters and vocabulary, beautiful writing techniques, a relation to the readers. A truly strong and beautiful book overall.