I'll play some phenomenal games. I'll be completely aware calling out ganks for everyone, countering wards, always having tp's, denying exceptionally, and harassing a lot. I'll always pick heroes based on need and put forth a great effort.
This is not always the case, of course I have off games sometimes.
However I've noticed that more often than not I'll somehow end up on a team that has 4 random teammates, then on the other team there will be 3, 4, or 5 team mates who are all completely synced and my efforts are pretty much irrelevant due to a couple of shitbrain players on my team.
I can honestly say that I play on par with 1700 leveled players as I've matched them many times but I've NEVER made it into 1700, I don't know what more I can do except carry every single game.
The games I get to mid I win more often than when I'm jungle, lane carry, or gank/support.