(CNN) -- From World Cup football to competitive ice fishing, practically every sport has a rule-book somewhere that tells you what to do about a tie. Sooner or later, somebody usually wins.
What if both sides lose?
Democrats in the United States have what is now essentially a tie in the competition for their party's presidential nomination, and it could cost both Hillary Clinton and Barack Obama their chance at the White House.
It's ironic because Obama and Clinton have run terrific campaigns, drawing record numbers of voters to the primaries and caucuses that select delegates to the Democrats' nominating convention. The race is lively, fundraising is up and expectations are high.
The problem is the maths, and the maths is messy. Our estimate at CNN is that by mid-week, Obama had 1,608 delegates and Clinton had 1,478 (the winner needs 2,025).
There are still more primaries ahead. There are extra votes yet to be tallied, from party officials called Superdelegates. There is a chance that Michigan and Florida, two states excluded from the count because of scheduling disagreements, could get their votes included after all.
The various options to resolve the tie, and the arguments for and against them, are now getting almost as much attention inside the party as the candidates themselves.
But there is a larger fear: if the race drags on for months longer, or if a winner emerges in a controversial way, it will alienate voters the Democrats need if they want to win the 'real' election, for the White House, in November.
Imagine, for example, how young first-time voters will feel if their candidate loses because of an improvised rule change or the votes of high-ranking party insiders? A lot of people could be put-off the party for years.
How about one obvious solution? A Newsweek poll found that more than two-thirds of Democrats want Obama and Clinton to stop fighting and join forces, as president and vice president.
But the poll didn't ask people who should get the top job and who should settle for second.
And neither of them is volunteering.
So the race continues, without any clear idea of how it will be won, or when.
It would be a lot easier if we could just get Clinton and Obama to lace-up some boots, or cut a big hole in the ice. E-mail to a friend