Zuril: Are you sure the software is calculating the RDs correctly. There doesn't seem to be much variation in players RD and the are mainly around 160 to 190 ish. Other sites talk about RDs below 80 which seems to make more sense. There doesn't seem to be a correlation between number of games played and RD, one would expect high number of games to correlate with lower RDs. Also Garykevinware has an RD of 334 which isn't much below 350 even though he has played over 1000 puzzles. I may be wrong but it doesn't look right to me. Merry Christmas Datr.