I've been watching the US Open and well, feeling a bit tired and please join me as I turn this into an extended analogy.
One of the things that is often true about younger players is that they have skill, of course, and so much energy, but less pro experience. Players who are ten years older have simply played more games than you. They have more experience to draw from.
But younger players have a lot of energy. So if the game goes to extra sets, they eat extra sets for snacks. They bounce on their toes between points, not just to stay warm, but also because they are so jazzed to be playing.
And so the lack of experience can push you through errors like trying a fancy shot that didn't work, or focusing more on returning the ball and not planning for the shot after that. They can get run all back and forth by a more experienced player and just keep going.
And that works for a while. Sometimes four rounds of that catches up to you.
As an experienced player you can be strategic with your shots. You are accustomed to thinking through returning serves, when to move in and when to hang back, planning lobs and other things to keep your opponent expending lots of energy while you conserve yours. So if your opponent in the energizer bunny that's fine because you have the skills to wear them out until they make a mistake.
But of course some days the player with the energy wins, and some days the strategy and experience wins. And some days you thought you were the strategic player, but it looks like you're relying on energy and vibes today.
And some days you do what you can to survive long enough to get a nap.