Just four women in the post-1968 Open era have won singles titles on the slow red clay of Roland Garros and Wimbledon’s lightning-fast grass before their 20th birthdays. And as Mirra Andreeva, the 19-year-old winner of last month’s French Open, walked on to Centre Court here on Wednesday to face Barbora Krejcikova – herself already a winner of both European grand slams – she had fair hopes of joining Maureen Connolly, Evonne Goolagong, Chris Evert and Steffi Graf as the fifth name on the list.