I was just looking over this morning’s paper, and reading the story “Russian champion disses Jenn” about how pole valuter Yelena Isinbayeva was pretty sure that she was going to win the gold [which she did later today], and that Jenn Stuczynski was unlikely to surpass her. The third paragraph in the story read:

Asked if she was annoyed by media suggestions that Stuczynski was a challenger after her U.S. record vault of 16 feet, 3/4 inch (4.90 meters) earlier this season, Isinbayeva was utterly dismissive.

This was followed shortly by a quote from Isinbayeva:

“They said, ‘Wooooo’ when she jumped 4.90 (16 feet, 1 inch), but I jumped this height four years ago. It is nothing special.”

Personally I think that vaulting over 16 feet is pretty special indeed: I believe these are the only two women who have ever done it. But what caught my eye was that 4.9 meters was stated as the equivalent to 16 feet, 3/4 inch in the first case, but was translated to 16 feet, 1 inch in the second.

So I checked. It turns out that 16 feet, 3/4 inch is 489.585 cm, which does round to 4.90 meters. Furthermore, 4.90 meters is 16 feet, 0.91 inches, which rounds to 16 feet, 1 inch. So my initial thought was that everyone was just rounding.

Then I checked the USA Track and Field conversion site which had the same hedging, but in the opposite direction — everything is rounded down instead of up. It says 16′ 1″ should be converted to 4.90 meters, but 4.90 meters should be converted to only 16′ 3/4″ . And what should 16′ 3/4″ be converted to? To 4.89 meters. Which converts to 16′ 1/2″. Which converts to 4.88 meters. Which converts all the way down to an even 16′. And of course 16′ converts to 4.87m, which converts to 15′ 11 3/4″, which — hold on to your hats here — also converts to 4.87m. Finally, a fixed point!

And by transitivity of conversion, we have that 16 feet, 1 inch is equivalent to 15 feet, 11 3/4 inch.

*Photo (cropped) of Yelena Isinbayeva by Eckhard Pecher, published under Creative Commons Attribution 2.5. *