The rules keep the wall in play.
The boards close the geometry. A pass that would leave a traditional pitch stays alive, returning at a new angle before the defence can reset.
Indoor soccer did not make the field smaller. It removed the touchline, and every rebound became a pass.

The boards close the geometry. A pass that would leave a traditional pitch stays alive, returning at a new angle before the defence can reset.
Players learn to see the rebound before it happens. The fastest route forward is not always a straight line.
Compact space and continuous play create the defining rhythm of the indoor game: pressure, release, ricochet, finish.
Scrub the sequence or press play. The green line is the pass; the boards create the opening.
The archive settles the argument on its own. On 21 May 2005 the Milwaukee Wave beat the Cleveland Force 10-9 in double overtime of the Championship Series Finals, in front of 9,279 at Savvis Center. After 84 minutes of play the winning goal came off the boards: Todd Dusosky caught a Matt Schmidt deflection and knocked it past Force goalkeeper Jim Larkin. The rebound was not a broken move — it was the assist.
That is the shape of indoor soccer in one sequence. The report also records the opening goal at 0:16 and a Cleveland goal two seconds into a man advantage, which is what a sixty-minute game on an arena floor does to the clock: events arrive at a density the outdoor code has no room for. The full report is in the archive.
The boards keep the ball live, so a miss becomes a pass. The rules that govern it are set out on the rules, and the league's own 2006 rulebook; the 2004-05 and 2005-06 editions are on the archive index.
It removes the touchline. A pass that would leave a traditional pitch hits the boards and returns into the attack at a new angle, so the boundary is where the next move begins rather than where play stops. Four walls are in play at once.
Sixty minutes, played in four quarters rather than two halves.
Five to six a side, on a surface far smaller than an outdoor pitch — which is what compresses the game rather than slowing it down.
In the league's own indoor soccer rulebook as it stood in 2006, forty-one pages, linked from this site as a PDF. It is one of five documents the MISL published alongside its reports; the 2004-05 and 2005-06 editions of the same rulebook survive as well.
The reports and the rulebook describe a continuous game: because the boards keep the ball live, there are far fewer restarts than in the outdoor code, and the rhythm the archive returns to again and again is pressure, release, ricochet, finish.