your average isn't based on your most current rounds. It is based on the best 50 rounds at your tier. You have won some Ready gos, and have played match play and it appears you defeated a Legend at least once and WGT adjusts your average for your match play results if you beat someone in a higher tier, and if I am not mistaken, it adjust if you have wins in the ready go's as well.
They made that adjustment some time ago in a move to help stop sandbagging, and I am not saying you are sandbagging, just trying to help you understand what is going on with your average.