ENNEADS

Squares in a sudoku, e.g.

• Baseball lineups, e.g.

• Diamond complements

• Diamond groups

• Ed's 11A crazy Anne's nine-piece sets (7)

• Groups of nine

• Muses et al.

• N.L. teams, e.g.

• Near-decades

• Nonets

• Sets of nine

• Supreme Court groupings

• Supreme Courts, e.g.

• The planets and others