He has bred a Triple Crown winner, but John Gunther has yet to have his first superstar as an owner. He's hoping that may soon change. Gunther is the owner and breeder of Stage Raider (Pioneerof the Nile), a half-brother to Triple Crown winner Justify (Scat Daddy), who will make his debut in Saturday's sixth race at Gulfstream. And while no one is predicting that Stage Raider will win the Triple Crown, both Gunther and trainer Chad Brown are optimistic that the 3-year-old colt has above average talent. "He seems...