Every Tuesday, this site examines a training or technology concept that shapes how tennis is played. This week, we are returning to the Tennis Channel’s Bag Check series, where professional players empty their tennis bags to reveal what they carry around with them.

Today’s inspiration comes from a video featuring former World No. 1 Ana Ivanovic. The video was posted more than fifteen years ago, and may have been filmed even earlier. Among the assorted items Ivanovic pulled from her bag was an impressive collection of hair ties. There were enough of them that Tennis Channel subtitled the segment, “Ana Ivanovic has so many hairbands.”

As it turns out, so do I.

Keeping my hair out of my face is a basic requirement for playing tennis, and a broken hair tie can become a surprisingly irritating equipment problem. I have had them snap at inconvenient times. It is also not unusual for me to arrive at a tennis match only to discover that I forgot to pack one with my tennis clothes.

Like Ivanovic, I have learned to keep a generous supply of spares with my tennis equipment. However, I have a slightly different approach to storing them. Rather than tossing a handful into one of the compartments of my bag, I keep mine threaded onto a small carabiner clipped to the outside.

That arrangement has a couple of advantages. First, I can immediately see whether I have an adequate supply. More importantly, if a hair tie breaks during a match, I can retrieve a replacement without much delay at all. The same collection provides insurance against those occasional failures to remember one in the first place.

A carabiner is inexpensive, takes up practically no space, and provides a convenient way to keep the entire collection together. It is a minor organizational improvement, but one that has worked well enough that I have been using it for years.

I have always enjoyed the Bag Check videos because they occasionally reveal small practical details that are easy to borrow from professional players. In this case, Ivanovic and I share the habit of carrying a lot of hairbands. The only difference is that I prefer to keep mine outside the bag.