I've been busy with work and then travel over the past two days, but tonight I was able to get to work on a list of tables and fields that I think would be relevant for a soccer match database. There might be other fields that other users would put in for other competitions, but I just wanted to set up a "base" database design.
I wrote down a list of the proposed tables and the data fields that I think belong to them, and generated a PDF file that you can download here. I need to put together a schematic that shows how the tables relate to each other, but it's late and that will require some time.
Like I said, I greatly appreciate your comments. I know that a lot of people would be interested in an effort such as this, and I also know that a lot more people have expertise with database design than I do, so I'd like to take advantage of the collaborative opportunities that the Web has to offer.