On television, she looked shorter. Perhaps this is an odd thing to say at the beginning of a farewell column about Monica Seles, but that’s what came to mind when I learned of her retirement last week.

Usually a tennis player’s off-court looks and personalities influence, or mimic, depending how you look at it, their styles on court. The imposingly built and athletic Steffi Graf was an intimidating athlete between the lines. John McEnroe was volatile and quick-witted with his tongue and his racquet. Pete Sampras loped on court and off, and won matches without looking like he was trying, even when he tried his hardest. Stefan Edberg’s wispy hair and calm personality reflected his graceful and precise tennis. Boris Becker’s looks matched his play: explosive, flashy, powerful. So did Ivan Lendl’s.

Seles, who officially retired last week after not playing a match for nearly five years, was a different sort of champion. Tennis transformed her from a tall (5-foot-10, though my guess is she’s at least an inch taller) giggly, seemingly harmless teenager, and later an elegant woman (hence her new gig on Dancing with the Stars), into a feisty competitor who looked, frankly, like a pipsqueak compared to Graf (who is, by the way, an inch shorter that Seles). Seles’ two-handed strokes caused her back to hunch when she played, but even without the two-fisted attack, she would have been lower to the ground than her rivals and running harder (not gracefully, but not clumsily, either—“purposefully” is perhaps the best word). She always gave the sense that she was bearing down on an opponent, getting ready to barrel into her and take her out with a knee-high tackle. For three years, from 1991 to early 1993, she cut down everyone, winning seven of nine major titles and capturing the no. 1 ranking at age 17.

The “What would have been?” game, so often played by sports fans, can be a tiresome and pointless endeavor. It’s not in the case of Seles, because we can be fairly certain what would have happened had Gunter Parche, a deranged Graf fan, not stabbed the 19-year-old Seles in the back with a 10-inch boning knife in April 1993. Seles would have continued to win, and win a lot. At the time, she was preparing for a run at her fourth consecutive French Open title. Later in the year she would have tried for her third consecutive U.S. Open title. In between, she would have had another chance to solve Wimbledon, the place where her grunts received the most criticism and where Graf’s serve and forehand were most effective. Instead, she didn’t play again until 1995. Graf won the 1993 French Open and the next three major titles, too. She won 11 of her record 22 majors after the stabbing.

How many more majors would Seles have won? I’d bet (I’m of Italian heritage, after all, and as Giorgio Galimberti reminded us this week, gambling is in our blood) that she would have won at least five or six more, bringing her career from nine up to 14 or 15. Graf might have won five or six fewer, reducing her career total from 22 to 17 or 16. Graf, without question, is the greatest women’s player in history. If Seles had not been robbed of 28 months in the prime of her career, though, there might be a lot less distance between Graf, Martina Navratilova, Seles, and Chris Evert.

Seles’ return to tennis, in 1995, is often seen as disappointing. I think it’s remarkable. After two years away from the game—after being stabbed in the back—she won her first tournament (she lost 14 games in five matches) and reached the final of her first major, the 1995 U.S. Open (she didn’t lose a set until the final, which Graf won 7-6(6), 0-6, 6-3). She won the Australian Open a few months later. Granted, Seles never quite looked the same and never won another major. But considering her injuries—both physical and psychological—it’s remarkable that she met with any success at all once she returned.

When Maria Sharapova won the Australian Open last month, most commentators remarked on her intensity, her competitive spirit, her dogged approach to the game. Seles once played like that—for two consecutive years. In 1991 and 1992, she entered seven majors (she missed Wimbledon in 1991) and won six of them. She lost the other, Wimbledon in 1992, in a final memorable not only for its lopsided score (6-2, 6-1) but because Seles refused to grunt because several of her opponents had complained. Other than that final, Seles had owned Graf in important matches: she won their other three major final meetings, including a 6-2, 3-6, 10-8 victory at the 1992 French Open.

Looking back on Seles, one thing stands out: her grit. She showed it during her best days, during her comeback, and in recent years, too, when she couldn’t quite convince herself that she wouldn’t compete again. In sport that has had many determined champions, she was the most determined of them all. Nine majors or 19, that’s what I’ll remember her for.