Hi,
Found some interesting things they use as tie breakers, keep in mind when composing:
1st tiebreaker: Highest Overall Strength of Submission score
2nd tiebreaker: Highest Prose/Style score
3rd tiebreaker: Highest Plot score
4th tiebreaker: Highest Character Development score
5th tiebreaker: Highest Originality of Idea score
6th tiebreaker: Amazon editorial decision