Mad rush of activity on ESPN's tournament website

Louisville's Kevin Ware (5) celebrates after making a

Louisville's Kevin Ware (5) celebrates after making a three-point basket during the second half of the Big East Championship title game against Syracuse at Madison Square Garden. (March 16, 2013) (Credit: AP)

The last of the teams in the NCAA Tournament was announced at about 6:39 p.m. Eastern Time Sunday. By 6:44, ESPN.com's 16th Men's Tournament Challenge was up and running, ready for the annual online deluge.

So what took you guys and gals so long?

"We took an extra five minutes to make sure everything was up there and looking the way we wanted it to look," said Jason Waram, whose fantasy job at ESPN is vice president of fantasy.

This was 23 hours later, by which time, Waram said, "from a technical standpoint, we're kind of on a down slope."

But those five minutes Sunday were the peak of an intense day, during which 35 technical experts in a Seattle office spent 12 hours setting up and then executing a contest that last year drew a record 6.45 million entries -- including that of President Barack Obama -- and, based on early trends, is expected to surpass that total handily.

At its peak, the contest was receiving 6,340 brackets per minute last year, the kind of efficiency that has turned what used to be a pastime built around Xeroxed copies of brackets in office pools into a massive group event orchestrated by online giants such as ESPN, Yahoo and CBS.

Waram said the only Web-based activity that draws more participation to ESPN.com than filling out NCAA brackets is fantasy football.

The latest boost has been the increasingly user-friendly ability to engage sophisticated apps for mobile devices.

"It gets easier and easier,'' Waram said. "We saw Sunday at the minute the bracket had finished being announced our mobile devices getting pounded."

Sunday night typically is the second-busiest time for bracket-filling, with the busiest being Wednesday night and into the hours before tipoff Thursday. (ESPN and most other sites do not require picking the First Four, thus giving fans more time to fill in their brackets.)

This year's tournament has been called the most wide-open in years, a fact that is reflected in early entries.

Waram said last year, about 35 percent of all brackets had Kentucky winning the national championship, an unusually high figure for one team.

As of late yesterday, there were several teams picked to win in more than 10 percent of brackets, led by Louisville at 21 percent and Indiana at 17.

"Overall, who has been picked has been much more diverse this year than last year," Waram said.

The downside of that is that while millions of fans in 2012 remained engaged to the end because Kentucky lived up to its billing, this year there could be millions of brackets busted early, which would dampen interest among casual fans.

Fans are permitted up to 10 free entries for ESPN's men's and women's bracket contests. Those who finish in the top 1 percent are entered in a drawing for a $10,000 Best Buy gift card for the men's and $5,000 for the women's.

The ESPN bracket contest is as good a measure as any of the collective wisdom on the tournament -- flawed as it inevitably is. That is what makes it fun to watch as the numbers pour in, even for the technical wizards behind it all.

"Oh, yeah, absolutely," Waram said. "We want to make sure everyone who wants to get a bracket in gets a bracket in -- and we want to see how people are doing."