If you've been watching a lot of NBC's Olympics coverage, you've probably seen this Subway commercial. "Try avocado on any sub," beseeches winter Olympian Apolo Ohno. And then this graph appears on the screen. What does this graph mean?

While roughly ninety percent of the commercials broadcast during the Olympics are advertising NBC's new shows — Old Matthew Perry, Sexy Fire Department, and Arrested Modern Family Development Sunshine — the other ten percent are more traditional Olympics advertising campaigns in which athletes eat food.

The Subway spot — which features no Olympians who are actually participating in this summer's games — shows the enticing graph, labeled, somewhat confusingly, "avocado." It's unclear, among other things, what's being measured on the graph; when I asked on Twitter, people had a variety of readings:

"Avocados over time" was by far the most popular interpretation of the graph. But I found it unsatisfactory: if "avocado" is mean to indicate the y-axis, why is it above and parallel to the x-axis? Furthermore, such an interpretation only opens up more questions — does avocado increase over time in the context of Subway sandwiches? Worldwide?

Still mystified, I emailed the company to find out. I heard back this morning:

Given the sports science nature of the spot, the graph was designed to draw the eye upward in trend - a trait we typically perceive as positive. In this case, we thought of the upward (positive) trend as related to taste, as in Avocado increasing the taste factor of said sandwich.

So: yes, "avocado" is the x-axis; the y-axis is "taste factor." As avocado increases, taste factor multiplies exponentially.

Subway provided no peer-reviewed studies or sources for the data.