The player’s rank is calculated using MMR (MatchMaking Rating). The value of this indicator depends on your statistics, ranks of allies and rivals, as well as a number of other factors. Rank in Competitive Mode is only affected by MMR points. You can see the number in your profile, or after a match in Competitive mode. In the second case, you will see how the result of the match affected your progress. The changes in your MMR are influenced by:
The difference of the total MMR of your team in comparison with the total MMR of the group of opponents;
The number of rounds won and lost;
Your personal performance in the match.
Once you have reached a certain amount of MMR, you will receive the next rank. In the event of a constant decrease in MMR, you will downgrade to the previous rank.