Greg Maddux threw a 96 pitch complete game tonight for his third victory of the year. That puts him at 336 career wins, tenth in history behind, uhhh, Tim Keefe. If he stays healthy, and if the Padres score enough runs, he's got a decent shot of passing Keefe this season.
Meanwhile Clemens has 348 wins, and will pick up a few more this season. This is, by definition, rare. I can't imagine there will ever again be a time when two of the ten all time winningest pitchers are simultaneously playing. (If Maddux gets seven more wins, it'll take 342 to even make the top ten, and in this day and age I don't see anyone getting to that point ever again.)
Because Clemens and Maddux have such a good overlap, we can compare their win totals. Clemens started in 1984, Maddux in 1986. This chart shows Clemens' lead, which was 59 wins in 1991 and has been shrinking ever since:
I have no idea whether it's true, but it wouldn't surprise me if this was at least part of Clemens' motivation to come back again. He wants to be the greatest pitcher of his generation, and that's a bit tougher to justify if someone else of his generation has more wins....