Ok Paddy, An Irish Trainer engages a top jockey to ride his horse and gives intructions: "When you come to a jump, say "Up and over!" Coming to the first fence, the jockey ignores the instruction because the horse would obviously know what to do. But it blunders through the first and second fences. So he follows instructions and shouts "Up and over!" at each succeeding fence and the horse jumps like a stag and wins the race.
Back in the enclosure, the trainer asks what happened at the first two fences? Covering up, the jockey says: "I think your horse is deaf." The trainer repies: "Oh! I didn't know that. I knew he was blind."