Think of a regular chicken breast as a giant, stubborn iceberg. A split breast is that iceberg cracked in half, with a bit of wing bone still attached for flavor. It’s like the chicken decided to wear a tiny drumstick hat.
Butchers call it “split” because it’s literally split down the middle, skin still on, bone still in. This means it cooks faster than a whole breast but stays juicier than a boneless, skinless sad-sack. It’s the Goldilocks of poultry parts: just right.