Op is lying, you cannot get over 55% winrate past diamond rank because of the algorithm, thats how blizzard have designed the game its been confirmed by blizzard in this post
quote from blizzard poster: A: Since each player starts at the bottom of the ladder at start, we want fair matches for everyone (aka. win-rate close to 50%). At that time, your progression on ladder is protected by your star bonus, thus your net expected gain will be positive through the ladder. Once other players run out of star bonuses, matching by rank will allow for good players, or players who want to push themselves a bit, to be able to progress to a higher rank.