Women who won 3/4 slams in a year
... AND did not play in the OTHER slam they didn't win.
Helen Wills Moody (1928 and 1929)
Billie Jean King (1972)
Monica Seles (1991)
Steffi Graf (1995 and 1996)
Serena Williams (2002)
First, I was surprised there were so few.
Second, who and in which years had the biggest chances to complete the Grand Slam (if they had played in the other slam). Let's not talk about Steffi Graf too much here since she has done it already and twice, LOL.