In America, there's hardly a one -- not anymore, anyway. Because in America, we have winners and we have losers, by God, and ties are for losers. We haven't always been anti-tie, though.
As a matter of fact, in NFL football -- which is arguably replacing baseball as the most American sport -- ties are still technically allowed, although they hardly ever happen. They used to be pretty common, though; prior to 1974, in the regular season, there was no such thing as overtime -- that only happened in the playoffs. When the game was over, it was over.
In 1974, the NFL instituted sudden-death overtime in the regular season, meaning one fifteen-minute overtime period was added, with any team scoring during that period declared the winner.
It's less well known, though, that to this day, if nobody scores in that one overtime period, the game ends in a tie (in the playoffs, overtime continues until someone wins). Interestingly, the first game played under the new rule (between the Denver Broncos and the Pittsburgh Steelers) in 1974 still ended in a tie.
As time has drawn on, though, ties have become less and less common. After a six-year interlude, the last one was a 13-13 sister-kisser between the Cincinnati Bengals and the Philadelphia Eagles in 2008. So rare was it that Eagles quarterback Donovan McNabb was pretty surprised about it--he didn't realize ties were even allowed.
Fewer people will be surprised to learn that in hockey -- which is pretty much like soccer on ice plus violence -- ties have historically been allowed. But in 2005, when the NHL came back from the epic fail of the lockout labor dispute that killed the 2004-2005 season, the establishment introduced a bunch of fancy rules.
Aside from making the game less violent (boo!), the NHL fat cats also bowed to American win-lose pressure and killed the tie. During the regular season, games go into a five-minute overtime period, and if nobody scores, then a shootout, where players go one-on-one against the goalie, three at a time, until someone scores more points. There can be as many shootouts as necessary to settle a game. In the playoffs, games go into overtime periods, twenty minutes each (just like regular periods) until someone comes out ahead.
Hockey is arguably a Canuck sport anyway. In truly American sports like basketball or baseball, ties have never even been considered -- although in Japan, baseball games end after twelve innings, so everyone can get to the subway before it stops running. And here in the States, baseball games are occasionally called a draw due to weather.
Soccer leagues around the world have occasionally experimented with killing the tie. In fact, as the World Cup heats up and teams proceed to the knockout round (the World Cup equivalent of playoffs), the tie disappears, and teams play into overtime and then, like in hockey, shootouts.
In regular soccer games, though, the tie is not likely to go away any time soon. Despite the attempts of various soccer leagues to lure in U.S. fans by getting rid of the tie, the reality is that there's a disconnect. Casual fans might not like it, but to hardcore soccer fans, the ones that actually go to games and provide Major League Soccer its bread and butter, to those folks, ties are as integral to the fabric of the game as silly knee socks.
Just ask Seattle goalie Kasey Keller, who told ESPN that eliminating ties in soccer would be like making a half-court basketball shot worth five points. "You can make fucking stupid rules about everything," he said, " but the sport's rules are the sport's rules."