Belmont averaged a 10.5 overnight household rating from 6:15 to 7:15 p.m., according to Nielsen, 169 percent better than last year’s 3.9 overnight rating.

The ratings spike came courtesy of Big Brown, the Kentucky Derby and Preakness winner who was trying to become the first horse since Affirmed in 1978 to capture the Triple Crown.

Big Brown failed in his bid, but he helped contribute to a much larger trend being seen in sports this year, that of viewership increases after years of steady sports ratings declines.

“I think it's a happy coincidence,” says Steve Sternberg, executive vice president of audience analysis at Magna Global. "Good storylines, teams (or horses) going for record achievements, classic confrontations, all contribute to high ratings.”

The surge has been seen across nearly every sport in 2008. The recently concluded Stanley Cup finals almost doubled last year’s worst-ever ratings on Versus and NBC, and marked the best performance for the National Hockey League since 2004.

The National Basketball Association finals are up more than 50 percent over last year, after seeing double-digit increases for earlier postseason rounds on cable and broadcast.

NASCAR last week ended its first half on Fox with its first year-to-year viewership increase since 2005. That comes months after the most-watched Super Bowl ever in February. Even WNBA ratings have soared by double-digit percentages this year.

Contrast that with primetime broadcast viewership, where the Big Five networks were down a collective 6 percent during the recently concluded television season.

While it might be tempting to attribute the sports increase to a larger trend, the reality is that this pattern is probably simply a reflection of a year of great storylines that coincidentally came at the same time.

There’s a strong one behind virtually every sports ratings uptick this year. The Super Bowl featured a squad, the New England Patriots, attempting to become just the second undefeated team in modern history.

The NBA finals are a rematch of two bitter rivals from the 1980s. The NHL finals featured the league’s top young player, Sidney Crosby, against its most storied U.S. franchise, the Detroit Red Wings.

The WNBA’s first two games on ESPN2 were up 44 percent over last year, coinciding with Candace Parker’s entry into the league. Parker became the first girl ever to win the McDonald’s All-American slam-dunk contest in high school and later led Tennessee to back-to-back national titles.

And of course the Belmont spike came courtesy of the latest in a line of nearly a dozen horses in the past 30 years to attempt to capture the Triple Crown.

“San Antonio versus Boston, or San Diego against the Giants would not have done nearly as well,” Sternberg says. “Had Big Brown lost the Preakness, ratings for the Belmont would have been much lower.”

Still, the increases are all relative. Viewership for some sports will never rebound to the levels it was a few years ago, when the media landscape was less fractured.

The NBA finals look great compared with last year but not so spectacular compared to four years ago, the Lakers’ most recent finals appearance. That year game one drew 2 million more total viewers than this year’s opener.

Though the NHL grew a lot compared with last year, the series still only averaged 5.4 million total viewers, or about half the number who tuned in for the premiere of “Million Dollar Password” a week ago.

And the Belmont was off 33 percent from the last time a Triple Crown contender raced, Smarty Jones in 2004.