Shutting the Door

Shutting the door is a defensive driving technique in motorsport where the leading driver moves to block the racing line—typically by taking the inside position into a corner—to prevent a competitor from overtaking.

When two race cars are battling for position, the driver in front doesn't just wait to be passed. They can use defensive tactics to protect their spot, and shutting the door is one of the most common moves. Think of it like closing a door before someone can walk through it—the lead driver moves to cover the preferred passing route before the chasing car can get there.

This maneuver usually happens as drivers approach a corner. The racing line is the fastest path through a turn, and it typically starts on the outside of the track, cuts to the inside at the apex (the middle point of the corner), and then exits wide. The inside line at corner entry is where most overtaking attempts happen because a driver can brake later and dive up the inside.

To shut the door, the lead driver moves toward the inside of the track early, before the braking zone or at the very start of it. This positioning blocks the inside passing lane and forces the pursuing driver to either back off or try a much more difficult pass around the outside. The key word here is "early"—the move must be made before the chasing car is significantly alongside.

This defensive move is generally legal in most racing series when done correctly. However, there's a fine line between defending your position and illegal blocking. Blocking occurs when a driver reacts to the chasing car's movements by changing their line, essentially moving in response to where the attacker is going. Shutting the door should be a preemptive decision, not a reactive one.

Many racing series enforce a "one move rule," meaning drivers can make only one defensive move. You can't weave back and forth across the track or make multiple blocking attempts. Once you've moved to defend the inside, you must commit to that line. Making a second move to block is typically penalized.

Safety is crucial when shutting the door. If done too late or too aggressively, especially in the braking zone, it can cause collisions. The defending driver must also leave racing room—you cannot force another car completely off the track or cause contact. Race stewards watch these situations carefully and can issue penalties for dangerous or unfair defending.

While shutting the door compromises the ideal racing line and may cost some speed through the corner, it's often worth it to maintain track position. A driver who successfully shuts the door can then focus on getting a strong exit from the corner to pull away or at least stay ahead down the following straight.