Winning the WTA Finals, Steffi Graf once said, "makes a season a lot sweeter". Every time Fraulein Forehand played for the title, it was plain how much the tournament mattered to her. You could also tell from the way she dealt with adversity, including injuries, on court; a little pain, jeopardy and discomfort wasn't going to stop her from achieving her ambitions.
And that desire propelled Graf to five titles at the WTA Finals, which puts her level with Serena Williams in joint second spot on the historical leaderboard, trailing only Martina Navratilova's eight tournament victories.
On winning the title for the first time in 1987, by beating Gabriela Sabatini, Graf described it as the biggest victory of her career to date, above even the first Grand Slam that she had scored at Roland Garros earlier in the season. That wasn't just the post-match euphoria speaking - her rationale was that, to win the WTA Finals, you had to deal with an elite field, as well as coping with the tiredness and ailments that came with competing at the end of a long year.
Looking back through the history of the tournament, was anyone more adept than Graf at playing through pain? Consider how in 1989, though she had a sore and swollen ankle, she still defeated Navratilova in four sets in the final, with Navratilova disclosing afterwards that she hadn't detected any weaknesses in her opponent's movement and game (which tells you just how well Graf disguised her injury). And, before beating Arantxa Sanchez Vicario for the 1993 title, Graf required a pain-killing injection for her lower back, while she was suffering from blisters when she overcame Anke Huber in 1995 in what was the tournament's first all-German final. Graf's fifth and final title came in 1996 - this was the only time that she retained the trophy - when she won a five-setter against Martina Hingis. Afterwards, Graf was so happy she cried.
Mark Hodgkinson is the author of 'Game, Set and Match: Secret Weapons of the World's Top Tennis Players' (Bloomsbury, May 2015)