Last year, for the 50th anniversary of TENNIS Magazine, we focused on the past. Given the tome of stories we’d told, and the trove of players and matches we’d witnessed over the past half-century, it was only natural to look back.

And it was comical to even consider doing something similar this year, for the 20th anniversary of TENNIS.com. So we’re taking the opposite approach, and instead focusing on the future. All throughout the week, we’ll be talking about what’s next for the sport, the website and much more.

It wouldn’t be an anniversary, though, without a countdown. But how do you count down events that haven’t yet happened? By predicting what will come to be.

With that said, we present TENNIS.com’s 20 for 20: Twenty matches that we’ll still be talking about twenty years from now. We’ve restricted this list to matches that have taken place in the last 10 years—or, as 20 for 20 author Steve Tignor has put it, “The Golden Decade.” (If you haven’t read our 50th Anniversary Moments or Tournament of Champions, also written by Steve, I implore you to do so.)

It has been a bountiful time for tennis since TENNIS.com’s inception, and it’s anyone’s guess what the next 20 years will bring. But we believe that each of these matches will sustain the test of time.—Ed McGrogan, Senior Editor

This match happened nine years ago, but it feels like a different era entirely. You might call it the Era When Serena Williams Had a Real Rival. Quaint idea, right?

That rival was Justine Henin, and these two talents made for a contrast worthy of Borg-McEnroe and Federer-Nadal. Williams was the strong, powerful American with the two-handed backhand; Henin was the small, quick European with the elegantly wicked one-hander. Together they battled and inspired each other over 14 often hard-fought matches; Serena ended up winning eight, Justine six.

When they faced off in the Miami final in 2007, it was just their second meeting since Henin had won a controversial French Open semifinal over Williams in 2003. For the better part of an hour, she looked destined to repeat that result in Key Biscayne. Henin bageled a sluggish Serena in 26 minutes in the first set, went up a quick break in the second, and twice reached match point while serving at 5-4.

If we’re looking for a time-capsule example of Williams’ famous ability to walk to the edge of the cliff without falling off, this match is it. Suddenly making the shots she’d been missing, suddenly dictating rather than reacting, she won the next six games and closed the match with a trademark unreturnable serve.

“I just feel like when I get down, a part of me plays better,” Williams said, “and I think all champions have that. When I play well, there aren’t many players who can beat me.”

That’s as true in 2016 as it was in 2007, but Henin was one of the few players who could beat Williams on a consistent basis. This year at the French Open, Williams crushed the woman Henin is currently coaching, Elina Svitolina, 6-1, 6-1. It was enough to make you wish Justine had picked up a racquet and taken her best shot at Serena again.