Originally Posted by Midnight Ninja
It depends on your MC points. If you get more points in MC than your worst showing in a 500 series, then MC is counted, else the worst 500 is counted as your four.
Didn't know that.
Still, if you look at Djokovic's points breakdown his worst 1000 tournament (IW 90pts) is worse than his fourth 500 tournament (Rdam 180pts) but the 90 points are counted and the 4th 500 is not.