Backchecking helps a team defensively by providing support in the defensive zone. It allows players to disrupt the opponent's offensive flow, apply pressure, and force turnovers. By backchecking, players can close gaps, block passing lanes, and limit scoring opportunities. It also helps in transitioning from defense to offense, as players can quickly regain possession and initiate a counterattack. Overall, backchecking is crucial for maintaining defensive solidity and preventing the opposition from capitalizing on scoring chances.