A lot of the top 10 were from when you were able to count cards -- it has since been nerfed to shuffle ever single hand. Most don't play anymore and their statistics wont change because it's no longer good. That group that used it hard and got it nerfed since quit but they also had several other casino games figured out and nerfed and the bookies shut down for a new bookie version with live bets.
If there even is anyone in the top 10 in blackjack and is still playing...and is positive... they've likely figured out the programming to when those "good days" are and will take that to their grave. It is programmed and not a live dealer so it has to be programmed to behave a certain way... and good days are certainly possible to offset the days it bends you over and cleans your wallet out.