Using basic statistics, you can also conclude if whether or not you actually deserve to be at that elo. If we assume that you're better than your listed elo, you already count as one player less on your team who will suck/troll. This means your team has 4 opportunities for a troll/bad player to ruin your game, while the enemy has 5 open spots. This means, roughly speaking, and jumping a lot of math, that you should win approximately 5 out of every 9 games, which means your ranking should go up with enough games. However, if you're a poor player, the opposite is now true, as you have 4 slots to fill that require a good player to carry you, while the enemy team has 5 to carry themselves. Likewise, you should now be losing around 5 out of every 9 games in this situation, which would result in your elo going down.