The single worst part about sports is maintenance. The U.S. Open is no different: hundreds of tennis players from all around the globe makes for hundreds of racquets that need to be restrung on a daily basis.

We had the rare chance to enter the Wilson restringing center at the Billie Jean National Tennis Center in Flushing Meadows, Queens. There, we checked out the state of the art Baiardo stringing benches and the experts who spend long hours keeping all the racquets used in the U.S. Open in tip-top shape — by hand. Here's what we learned.

The People

Think of pro stringers like the equivalent of a race car pit crew.

Professional stringers get in early (around 7 or 8 a.m.) and string for about 12 hours straight. We're told one stringer can wire up a racquet every 20 minutes, or roughly 36 racquets per day. In a typical day, about 500 tennis racquet pass through the Wilson stringing room.

It's not as simple as snapping all the strings off a tennis racquet and rewiring those same strings in a crisscross formation. There's an art to stringing and each one is taken apart and restrung with a surprising amount of heart, we found. Talking with them, the stringers told us they think of each tennis racquet like their child — each one needs to be cared for and given a certain amount of attention, whether that racquet belongs to a relative newcomer player or a hotshot celeb such as Serena Williams.

Aside from giving each racquet new strings, stringers need to adjust each one for a certain level of tension, and tweak it to fit the needs of the player who will use it. Logos need to be applied, too, because decals fall off during matches and every racquet head and handle needs to be waxed until it's absolutely perfect.

No matter how fancy the machine is, stringing is tough. The stringers in the room looked super stressed out, judging from all the wrinkles on their foreheads and the looming 20 minutes per restring, but they're passionate about it. Some of them have been stringing tennis racquets for decades now.

The Machines

The Baiardo isn't a wooden workbench, it's built to adjust to the stringer, instead of the stringer adjusting to it. A touchscreen panel can raise the machine up, so that stringers don't need to hunch over it to work. And because each stringer is going to have their own settings on how, the Baiardo can actually save personal settings for up to six stringers.

At first it seems rather strange to see a tennis racquet being operated on, like it was some kind of complex supercomputer, but the swiftness in which the U.S. Open's 16 stringers are able to rotate, cut string, apply string, pull string, wax and then test the racquets in only 20 minutes is a testament to their expertise — without whom, pro tennis players would have racquets that are abused and aren't calibrated to their playing style.

See up close how the stringers work on their Baiardo benches in our gallery below, from mounting the racquets to stringing them up.

Baiardo, via U.S. Open

Disclaimer: DVICE was invited out to the Billie Jean National Tennis Center in Queens by Olympus as part of a U.S. Open photo shoot. All pictures were taken by Raymond Wong for DVICE using an E-PM1 Mini provided by Olympus using this crazy $800 lens.