OPM rightly points out that my comments only relate to dirt tracks, but I assume he is referring to the difficulty a handicapper would have measuring moisture content. As I understand it, these reasearchers collected 10 samples, weighed them, dried them in an oven at 100 degrees C, and then reweighed them to determine moisture content. Though it would have cost quite a bit more, they could have measured moisture content and quite a few other things if they had used a device invented more than 20 yrs ago by the M.I.T. Engineer who was instrumental in the design and construction of Tapeta, the only training track I know of which will pay for the surgery if a horse in training experiences a chip, fracture, or quarter crack. OPM is also correct that the basic point has to do with how moisture content(perhaps because it is the only thing they looked at) appears to have a different impact depending on how fast a horse runs. For safety purposes, it might make sense to run the races for slower horses with the moisture content at one level, and the races for faster horses with the moisture content at another level. The link to research paper is: http://www.neosoft.com/~iaep/pages/protected/jissues/j1701/1701_3.html

As you read it, imagine the energy returned by the track in terms of a series of springs, and tell me if logically a larger surface area would result in more rebound, assuming a cushion which contains the right level of moisture for a horse that speed.