When he was obtained by Hugh Wiley, Wiley enlisted the help of the United States Equestrian Team coach, Bertalan de Nemethy, and together the two men trained the horse to be the Olympic-level open jumper he became.
The passage describes how Hugh Wiley obtained a horse and then worked with the US Equestrian Team coach, Bertalan de Nemethy, to train it for an Olympic-level competition in the open jumper category.