Move all the MLB baseball fields 5 feet closer to the outfield fences. This will allow a return to steroid-era homerun levels while also ensuring a large number of foul balls are now converted into outs. If teams did this one foot each year for 5 years, they could do it on the sly without their fans ever being the wiser. ("Boy, that Doug Bernier has really developed some power!")

 

Note: The Oakland A's would just move their fences in, since they already have the desired amount of foul territory.

 

 

How does this shorten the game?

It removes the incentive to bring in wave after wave of relievers.  "Why should I bring someone else in?  The fences are so close, it'll just be the same."

 

_{^{/ When I first moved to Nevada I went to a Reno Chukars independent league game.  The score was something like 7-5 in the fifth inning, and both starters were still pitching despite having given up some homers.  The above logic, thin air moreso than close fences, seemed to hold sway with both managers that evening.}}

I think this is the best idea I've heard so far.