In the long jump, a foul occurs if the athlete's foot touches what part of the takeoff board?

In the long jump, a foul (also called a scratch) occurs when the athlete's foot crosses or touches the ground beyond the front edge of the takeoff board. The takeoff board has a clearly marked front edge known as the foul line (or scratch line). A plasticine indicator strip is typically placed just beyond this edge to record any contact. If any part of the jumper's shoe breaks the plane of the front edge and touches the ground or the plasticine beyond it, the jump is declared a foul and the distance is not measured.

The other options are incorrect:

• There is no red warning strip on the side of the runway in standard long jump competition.
• Touching the sand pit before the jump is not the specific foul condition. The foul is determined at the takeoff board, not at the pit. (Landing short of the pit would simply result in a short jump, not a foul.)
• Touching any part of the takeoff board before the white line is actually legal. Athletes are supposed to place their foot on the board; the foul only occurs when they step beyond its front edge.

Athletes practise their run-up carefully to hit the board as close to the front edge as possible without crossing it, maximising the legal distance of their jump.