What is the [need] column?

The [need] column represents the number of games a player must complete to have an active rating in a specific category.

Each rating is either active or inactive. A player's blitz rating is active if that player has played 8 rated blitz games in the last 31 days. The requirement is also 8 games for bullet ratings to be active.

For standard and wild games, the requirement is 6 games per month. For 5-minute, 3-minute  and 1-minute, it's 8 games in one week. For 15-minute it's 4 games in one week. For correspondence it's 2 games in one year.

Games in which you do not gain any points with a win do not count towards being active. People who are not active are not listed on the "best" list or counted in the "stat" command. They also won't appear in "rank".