Some players have contacted us, asking to remove certain games, or give them 'fresh starts' because they did not know their early games were their 'placement' matches.
Starting with a losing streak is unfortunate, but so is starting with a winning streak. For example, we've won all 5 of our first placement matches in Starcraft 2, and got placed in Gold league. We were excited, we bragged to our friends who were placed in Bronze or Silver. We knew we had some lucky games, but the end result is what matters. And then we lost 13 games in a row and was dropped to Bronze. We shouldn't have been placed in Gold league to begin with, and as time went on and we've played more games, Blizzard's matchmaking became more confident and accurate, and we started winning 50% of our games.
The reverse is true here: If you had a losing streak in your 'placement matches' on HOTS Logs, then you will start with a pretty low MMR. If this is inaccurate, and your MMR truly should be higher, Blizzard will be placing you against teams with higher MMR. If you win 50% of your games against players with MMR higher than you, your MMR will slowly climb up to theirs.
Unfortunately, if your MMR has indeed been inaccurately affected by a losing streak in your placement matches, the solution is to just play more games. It may take more games than if you had won some of your placement matches, but your MMR will end up where it should be eventually. The solution here is not to delete the replay, though; this would remove the replay from the other 9 players in the match as well, and we need more replays uploaded in order to be confident in MMR calculations.