ReString at Mubadala Citi DC Open 2025

Picture this.

You're standing courtside at a professional tennis tournament, just steps away from some of the world's best players.

You're not watching from the stands or following matches on TV. You're part of their preparation.

This summer marked my fourth year as a hitting partner at the Mubadala Citi DC Open.

It's an experience that never gets old and always teaches me something new about the game we all love.

What Made This Tournament Special

This year's tournament featured one of the strongest fields in its history. Seven of the top ten ATP and WTA players in the world competed in Washington D.C.

The level was particularly high because of a unique calendar shift. For the first time, there was a three-week break between Wimbledon and the Citi Open.

Players had time to rest and reset before arriving, which made for sharper practices and more competitive matches.

Temperature Conditions

The conditions were brutal.

Temperatures reached 36°C (over 96°F) with oppressive humidity that made every practice session feel like a marathon.

The tournament used Wilson US Open balls, which bounce high and fly fast in these conditions.

Because of the heat, every session started with at least two new cans, and fresh balls were added every 30 minutes.

My Experience as a Hitting Partner

Being a left-handed hitting partner creates a unique dynamic.

The number of sessions I get depends entirely on how many lefties remain in the draw.

When several left-handed players are still competing, I'm in high demand. Players want to prepare for that specific spin and trajectory that lefties bring.

But when the lefties lose early, my phone goes quiet. Most right-handed players prefer not to hit with a lefty unless they're facing one in their next match.

Pro Players I Played With

This week I was fortunate to hit with some incredible players.

On the men's side, I trained with top-50 player Zizou Bergs, Emilio Nava, and Billy Harris before his match with Cameron Norrie.

The women's side gave me even more court time. I hit with Maya Joint, Kamilla Rakhimova, Varvara Lepchenko, and Anna Kalinskaya before her final against fellow lefty Leylah Fernandez.

Each session taught me something different about how pros approach their preparation. The intensity never drops, even in practice. Every ball matters.

Stringing Insights

Here's what most tennis players don't realize.

At the professional level, strings are pure science. Most players restring their rackets every time they step on court.

This isn't because strings are breaking. It's because string tension drops after about 30 minutes of play, and that tension loss affects control, feel, and timing.

During match days and practice sessions, players rotate through multiple rackets, which makes stringing rooms at tournaments incredibly busy.

At the DC Open alone, approximately 3,000 rackets get restrung in one week. At a Grand Slam, that number jumps to nearly 10,000 over two weeks.

Discussions With Pro Players

Between practice sessions, I had some interesting conversations with players about their equipment choices.

One player told me they had recently made a major change after nearly a decade of using the same setup.

They'd switched from a full bed of Luxilon ALU Power to a hybrid with natural gut mains and polyester crosses.

They explained how the change improved their feel and control while maintaining the durability they needed for their aggressive style.

It reminded me that even at the highest level, players never stop experimenting with their equipment.

For my own setup, I used a full bed of Zero at 54 pounds throughout the week. I normally string at 52.5 pounds, but the heat and humidity led me to bump the tension up slightly for extra control.

Conclusion

This year's DC Open reminded me why I keep coming back to this tournament year after year.

Every practice session, every conversation with players, every exciting matchup, it all adds another layer to my understanding of tennis.

As I packed up my racket after the final day, I was already thinking about next year's tournament.

The players will be different, the conditions will present new challenges, but it’ll be the same great fun as it was this year.

About the Author: Juan is the co-founder of ReString. He was born in Argentina, raised in Japan, and moved to the US to pursue college tennis. He now plays as an ATP & WTA hitting partner.