We analyze the impact of tear rotation on the tensile strength of reinforced natural rubber elastomers. Vulcanized natural rubber materials reinforced with carbon black or precipitated silica are studied. Single edge notched reinforced samples stretched at constant velocity exhibit an abrupt instability in the direction of propagation of the crack. This phenomenon has been known as tear rotation. The measured apparent tensile strength (in terms of energy at break) may be increased by a factor of 6-8 in some cases. A mechanism is proposed in order to relate the tensile strength of the material to the presence of tear rotations observed in reinforced natural rubber. This large increase in tensile strength associated with the presence of tear rotations is analyzed semiquantitatively, based on energetic arguments, without entering into a detailed description of the elastic strain field in the vicinity of the tear tip. We also show a correlation between the length of a rotation and the stress level at which it appears. The proposed interpretation is based on the idea that tear rotations relax the local strain (or stress) at the tear tip by creating a macroscopic tip radius. Materials reinforced with carbon black or precipitated silica aggregates show similar behavior.