What's the difference? The traditional lines separating the leagues are blurring, but when players swap sides they still need to make adjustments.(Baseball Season Preview)

Back in the day, the American and National leagues had different strike zones, separate offices and players who typically stuck in one league long enough to care about winning the All-Star Game. But free-agent movement, interleague play and a unified umpiring corps have eliminated the most obvious distinctions and most of the competitive spirit between the leagues. Now MLB is one big, happy family with Papa Bud and Uncle Don presiding over all. Or something like that.

For new Mariners first baseman Richie Sexson, the thought of changing leagues influenced his decision to leave the Diamondbacks about as much as uniform colors and types of pasta at the postgame ...