Split major connector is which type of stress breaker?
Split major connector (or) split lingual bar is a type II stress breaker. 
The major connector is split by an incomplete cut, parallel to the occlusal surface of the teeth into two units, namely upper and lower unit.
The denture base is connected to the lower unit and the rest and direct retainers are connected to the upper unit.
Type I
Type II
Type III
Type IV