Blind exchange in the 4×100 m relay: set the check mark, run off on a visual signal, keep the hand steady — including rules, mistakes and a test plan.
In the blind exchange, the receiving runner sets off as soon as the incoming runner reaches a check mark and takes the baton at full sprint without looking back. You may set the mark yourself: exactly one in your lane, made of adhesive tape in a distinctive colour, at most 5 × 40 centimetres [1].
The honest answer to how hard this is: it is the part of the 4×100 m relay where teams fail. In a computational study of the exchange, 25.5 % of teams at the then most recent World Championships were disqualified or did not finish [3]. And when the exchange works, it still costs time: in six national-level sprinters, the incoming runner's speed on entering and the speed at the start of the handover together explained 55 % of the variance in the 30 m zone time [4].
In addition, the ideal mark is not the same for everyone. In a computational model with four elite men the check-mark distance lay between 11.04 and 12.20 metres depending on exchange and lane, assuming a gap of one metre between the runners [3]. That is a model, not a field trial. But it shows that every mark has to be measured, not guessed. Realistically you need several sessions at speed until your marks are in place.
Younger athletes often choose standing, older ones the three-point start. The standing start offers a good view of the mark, the three-point start a compromise between acceleration and view [2]. In the lesson of the Federal Office of Sport, the take-off position from a standing start looking back is practised [6].
Milestone: you stand stably and see the mark without twisting your trunk much.
Start with a rough starting value and adjust it later. Orientation for elite men in the model: about 11 to 12 metres in front of you [3]; in youth athletics it is usually shorter. Placing the mark: adhesive tape, at most 0.05 × 0.40 metres, in your own lane, no second mark [1]. You may tear it into several pieces as long as it remains a single marker [1].
Milestone: the mark lies in your lane and complies with the rule.
You run as soon as the incoming runner reaches the mark. As the measure of punctual take-off, the release of the back leg counts [2]; the back foot is moved flat over the ground so as to accelerate with little braking impulse [2]. A race game such as a turn relay with a zone practises exactly this: run away when the incoming runner reaches the mark [6].
Milestone: 8 out of 10 starts without hesitation and without looking back.
The incoming runner calls. The outgoing runner stretches the arm back calmly and opens the hand [2]. According to the teaching material there should ideally be an arm swing between command and handover; youth athletes hardly manage that, so the focus is on a calm arm and hand position [2]. Do not look back: “Never looks back”, as a federation presentation puts it [5].
Milestone: 10 clean exchanges at a jog without looking.
Exchange at speed in the 30 m zone. The rules require that your run starts in the zone: you may not start running outside the zone, and your feet must stand in the zone before the start [1]. Move the mark by one foot after each run and document it.
Milestone: 8 out of 10 exchanges in the zone, the mark is noted.
In the blind exchange someone you cannot see runs at you at full speed. So: only after warming up, only on a free track, only with clear agreements. Do not leave your lane until the track is clear [1]. When practising at speed you build up bit by bit.
Muscles need protection too: 48 % of 357 athletes at the 2018 European Championships had had a hamstring injury at some point in their career [7]. This guide explains and motivates; it does not replace supervised training or a coach.
One mark does not apply to every exchange. In the computational model the mark had to lie in a different place for each of the three exchanges of a race and also depended on the lane [3]. So keep a small log: exchange 1, 2, 3, lane, mark in feet, result. Whoever knows their numbers does not have to guess in competition.
That is individual. In a computational model with elite men it lay between 11.04 and 12.20 metres, depending on exchange and lane [3]. In youth athletics it is usually closer. Test with video and move it by one foot after each attempt.
A single strip of adhesive tape, at most 0.05 × 0.40 metres, in a distinctive colour and in your lane. Further marks are forbidden [1]. The mark may be torn up and assembled into a marker of a different shape [1].
No, that is exactly why it is called that. You look at the mark or at the incoming runner when you set off, and afterwards only forward. The hand stays calm; the incoming runner pushes the baton in [2].
When the incoming runner reaches your mark. The rules require that your feet stand in the takeover zone before the start and that you do not start running outside the zone [1].
At the then most recent World Championships, 25.5 % of teams were disqualified or did not finish, as a computational study reports [3]. That is not a current figure. But it shows how important clean exchanges are.
Approach to the First Hurdle: Eight Steps from the Start to the Take-off