Most U.S. English speakers should be able to tolerate dialectal variants on some words and meanings, and maybe even have a passing familiarity with some idioms

Most U.S. English speakers should be able to tolerate dialectal variants on some words and meanings, and maybe even have a passing familiarity with some idioms and slang. I generally think sports metaphors should be out in international forums, and I'm not even sure they should generally be assumed in local forums either (I don't even have a passing interest in most sportsballs and sometimes have trouble following references even to U.S. local sports). Good points on the opposite meaning idioms. Perhaps the most right way to deal with things is to just use the number, or use scientific notation?