How does overwatch ELO work?

Related questions

1. How does Quickplay matchmaking work?
2. Is 1600 ELO good chess?
3. What is the highest level you can be in overwatch?
4. What level is Diamond border overwatch?
5. How much is overwatch on steam?
6. How does overwatch decide your rank?
7. What is my overwatch MMR?
8. Is there a monthly fee for overwatch?
9. What do levels do in overwatch?
10. Is there a level cap in overwatch?

Tags

1. #skill
2. #matched
3. #against
4. #matches
5. #players
6. #which
7. #assigned
8. #lower
9. #round
10. #expected
11. #rating
12. #overwatch
13. #numerical
14. #placement
15. #player
16. #higher
17. #after
18. #score