Backing up the bowler occurs when a fielder runs to a position behind the wickets to stop a throw from a teammate. This safety measure prevents the batting team from scoring extra runs if the primary fielder misses the stumps or the ball. Example: The mid-off fielder sprinted to the area behind the stumps to provide backing up the bowler during a run-out attempt.
Pro-Tip: Every fielder should move on every hit because overthrows are a common way to give away cheap and unnecessary runs. It demonstrates high team discipline and keeps the pressure on the runners to stay within their safe crease.