Personaly, when we play running situation, the RB is allowed to run until he's tackled OR he doesn't gain yard any more. I explain :
if the RB is tackled : board is switched OFF.
is the running back pivots himself and doesn't go forward anymore (= his base direction is STRICTLY to sidelines or backward) : board is switched OFF.
if the running back is blocked behind his own team (= rushing action behind a lineman,
RB base in contact with another team mate rear base side), after 3 seconds with no new significant progress, the board is switched OFF.
all other possibilities are not allowed in running game, including "rugby melee" style moves.
after a few games, we tried to clear some rules, especially the ingame duration times and delays. It 's why we allow duration for each offensive play possibility.
In fact, keeping the game on a strategic aspect, most of the board switching operations should be almost only managed by a neutral referee in our gaming style
It avoids the "chess issue" in passing play, for example : On a passing play, the offensive coach can let the board ON 3 seconds max. Then, once the baord is switched OFF, he has to call the pass and choose the receiver INSTANTLY. it simulates the QB tunnel vision, where decisions are made under pressure in a sec.
etc, etc... I know it depends of the coaches playing style, but personaly I prefer strong rules and no argument and discuss during play