The handover is the race: relay craft inside the changeover zone

What the zone actually demands

The exchange must be completed within a marked area, which means both runners have a fixed distance in which to solve a moving problem. The outgoing runner needs to be travelling near full speed when the baton arrives, or the team loses the momentum the incoming runner built. The incoming runner is decelerating by that point, so the transfer happens between one athlete slowing and another accelerating.

Getting the timing wrong in either direction is costly: too early and the outgoing runner must slow, too late and the exchange runs out of zone. This is why the exchange is rehearsed far more than the running itself, and why teams of individually slower athletes routinely beat faster ones.

The check mark

The outgoing runner does not watch the incoming runner and decide when to go; that reaction would be far too slow and too variable. Instead a mark is placed on the track at a distance determined in training, and the outgoing runner begins the moment the incoming runner reaches it. From then on the sequence is entirely rehearsed, with the outgoing runner accelerating without looking back and trusting the baton to arrive.

The distance of the mark depends on both athletes and on conditions, which is why teams adjust it between rounds rather than fixing it once. An error in the mark produces a visible failure, since the two runners either collide or separate and the baton cannot be passed.

Blind and visual exchanges

The fastest technique is a blind exchange, where the outgoing runner never looks back and receives the baton by feel alone. It preserves the outgoing runner's acceleration completely, since turning the head slows the body and disrupts the running action. Its cost is that it requires enormous trust and precise rehearsal, because there is no opportunity to correct a mistimed approach.

A visual exchange, where the outgoing runner looks back, is far more reliable and noticeably slower for exactly the reasons above. Teams choose between them on the basis of how much rehearsal time a pairing has had, which is why the technique varies by team rather than by event.

The hand and the call

The receiving hand is presented in a fixed position, held steady rather than reaching, because a moving target is much harder to hit at speed. The incoming runner places the baton rather than pushing it, and the placement has to reach the deepest part of the hand to be secure. A verbal call is usually used to trigger the presentation of the hand, since it removes the need for either athlete to judge distance visually.

The call has to be given at a consistent point, because a runner who calls early or late shifts the entire timing of the exchange. Under crowd noise the call may not be heard, which is why some teams rely on the check mark alone and rehearse accordingly.

Which lane the runners use

Within the lane the two athletes must not occupy the same line, so teams standardise which side each runner uses for each exchange. Alternating hands down the team allows each runner to hold one side of the lane throughout, which removes a source of collision. It also means each athlete rehearses receiving and passing with a specific hand rather than both, which improves consistency.

The pattern is decided by the running order and it constrains that order, since not every athlete is equally comfortable on both sides. These are small organisational details and they are the substance of relay craft, far more than the raw speed of the individuals involved.