The Chinese have been betting on cricket fights since the Sung Dynasty. They claimed that bigger-headed males were better fighters as far back as 800 years ago. It wasn't until recently that scientists put that idea to the test. In their experiments, they tested male field crickets in competitions where they paired males with similar body mass and size, but different head sizes. They found that males with larger heads won more fights than males with smaller heads.
You see, crickets with bigger heads have bigger weapons. Insects have mouthparts called maxillae and mandibles. Maxillae are used for swallowing and mandibles for grasping, crushing or cutting food. The size of these mouthparts depends on head size. They stick out from the front of their heads and make great pincher like weapons for grappling.