Have to agree with you EI - there are just too many factors that can influence the times - tactics, other runners, track condition (not all slow tracks are created equal!), etc. Saw the perfect example today (sorry - can't remember which race) when the winner was trapped in a pocket. When the jockey managed to get it out it easily out sprinted the other runners - no doubt the race time would have been quicker had that horse been able to get out earlier.