Occam's Razor points to a change in the ball as being the reason for the increase in home runs. But whether that is the reason or not I think it's time for MLB to consider tighter standards for balls. A 49-foot variation in the distance traveled of different balls is way too much. There should be two parameters tested on every baseball approved for use in games: hardness and air resistance. These would be easy to test. For hardness, drop a ball from a standard height onto a standard surface and measure the height of the bounce. The height of the bounce must be within a specified range or it's rejected. For air resistance, create a device which consistently propels a ball at a target at a standard velocity with a standard spin rate. The landing point must be within a specified range or it's rejected. This may lead to a fairly large number of rejected balls but those would probably still be satisfactory for use in minor league play. Beyond that, all baseballs must be stored at a standard temperature and humidity for a standard amount of time before testing and before being used in a game. (Are the baseballs used at Coors Field still being stored in a humidor?) I'm sure it would take several years for this to be implemented but it seems to me that this is an attainable goal. Among other things, research would need to be done to set the standards that would be used and the tolerance allowed. The standards that would be set should be subject to change during the first five to ten years after they are put in place. There are several ways that the standards could affect the game. Harder balls with less air resistance would be expected to increase the rate of home runs hit. Balls with greater air resistance would be expected to improve the ability of pitchers to throw breaking pitches. Harder balls would be expected to increase the risk of injury from thrown or batted balls. I'm sure there are other changes that would occur that I can't think of off the top of my head. Care must be taken not to micromanage in this area. For example, a rise in home runs could be due simply to several players having very good years. More importantly, those in charge would have a responsibility to determine what the game should be like. Should there be lots of home runs? Should there be lots of strikeouts? It's very likely that the standards eventually put in place would lead to other rule changes. The size of the strike zone and the height of the pitcher's mound are two examples of things which could be changed without making any fundamental changes in the rules of the game.