(deliberate conceptual tasks in support of the strategy) may include the following: Walling up: Two or more blockers skate together to make it difficult for the opposing team (especially its jammer) to maneuver. They may skate side by side and use a "wide stance" to maximize the blockade, but must not link with or grasp each other, or otherwise form an impenetrable connection. The ability to suddenly form a wall denies the opposition time to respond. A wall can inhibit, slow down, and ultimately trap the opposing jammer. An effective wall may last for an entire jam. Variations on the tactic include the following: Backwards bracing, in which one skater, forward of the wall, skates backward to sight the jammer and direct teammates forming the wall. A skater may break off from the wall to actively challenge the opposing jammer, with a teammate replacing the skater in the wall. If the opposing jammer tries to pass the wall on one side, players may abandon the other side to fortify the active side of the wall. Jammer tactics, in response to a wall or other obstacles by the opposing team's defense, include the following: Pushing through gaps in the wall or inducing the wall to separate by use of physical force. Evading the obstacle to one side or the other. Juking, where the jammer seems to be skating to one side but quickly shifts to the other side. Rolling around the end of the obstacle (spinning 360°) to end up ahead of it. Using teammates to impede the defense from adjusting, such as by setting screens. Using a whip, where one or more teammates grasp the jammer's hand(s) and swing the jammer forward, transferring speed and momentum to the jammer. Apex Jump: Using the inside curve of the track to leap out of bounds but land in bounds, passing opposing players. Goating: The pack is defined as the largest group of in-bounds blockers, skating in proximity, containing members from both teams. In the "goat-herding" tactic, one team surrounds a blocker of the opposing team and then slows so that that group becomes the pack. The rest of the opposing team, skating ahead, are thus put out of play and cannot legally block the goat-herders' jammer. Running back or recycling: When a skater bumps the opponent jammer off the track, the jammer can only re-enter the track behind the skater. The skater