High Roller-- People have said here several times some variation of, slow times are because of the horses, fast times are because of the track. If you go to the archives section of this site, you will see "Are Racehorses Getting Faster". If you read parts 1 and 1A, you will see that tracks are getting deeper, with the idea of making them safer, and sandier, with the idea of getting them to dry out quicker, which makes them slower when dry than those with higher clay content, and slower overall than those with less of a cushion.

Since there are no machines to tell us how fast tracks were and are, the best way to do it is exactly the way we do it-- as was pointed out by one of the scientists who has studied the surfaces themselves, see the quote in the DRF Expo presentation, also in the archives.