SARATOGA SPRINGS, N.Y. - Edgar Prado appears on the verge of winning his first Saratoga riding title, with a seven-win advantage over perennial champion Jerry Bailey heading into the final five days of the meet. But if the battle for leading rider should come down to closing day on Monday, Prado may wind up monitoring the race from the jockeys' quarters at Philadelphia Park, where he is expected to ride Harlan's Holiday in the $500,000 Pennsylvania Derby.