Complex sentence: But Hooper knew he was too talented to be relegated to horse racing, so he trained long and hard to master his craft and hone his skills, until finally earning his spot as the Pistons' official mascot.
Split into simpler sentences: But Hooper knew he was too talented to be relegated to horse racing. Knowing this, he trained long and hard to master his craft and hone his skills, until finally earning his spot as the Pistons' official mascot.