Think back (when we were all younger) to the NBA Professional League and the NCAA Basketball Tournament. It is well acknowledged that both sports had huge difficulties attracting fans because the games were simply boring
(click for reference quotes).
How many remember Tennessee's win over Temple in the 1973 season? Final score? 11-6. Yes, that was their basketball teams.
The NBA Shot Clock (1954) and NCAA Shot Clock (1985/86) saved both games and the experience that is now "March Madness" can trace itself to the introduction of the shot clock.
Now, lacrosse can dicker with the field dimensions, restraining boxes, and a host of other items. However simply put, the average fan wants more "action" ... the fan wants more shots per game. The lesson has already been learned in other sports.
The answer is a shot clock.