I'm curious where you picked up on the 29 foot stride. I remember listening to a derby broadcast in the early 50's and hearing the commentators talk about one of the horses having a stride of 30 feet. I narrowed it down to Native Dancer, Nashua or Swaps but I could never find anything in writing to pin it down. And by the way, if it hadn't been for sore legs Swaps might have been the best horse of the last 50 years. IN spite of his legs he still set a number of records.
