AsMarch Madnesstakes over this week, how many people are filling out NCAA brackets and why?A new poll fromThe Associated Press-NORC Center for Public Affairs Researchshows what share of Americans typically take a shot at bracket predictions and their motivation for joining in the madness.The survey found that about one-quarter of Americans fill out a mens March Madness bracket every year or some years. But what about the womens tournament? High-profile NCAA womens basketball games haveclosed the gapwith mens tournaments in terms of viewership and there is more money flowing in and around womens sports in general;womens teams will now be paidto play in the tournament, just like men have for years. It all points to higher interest in how womens teams fare even if the bracket frenzy has not quite caught up.The survey found that 16% of U.S. adults fill out a womens tournament bracket every year or some years. And its much more common for bracket participants to only fill out a bracket for the mens tournament than the womens about 1 in 10 U.S. adults only fill out a mens tournament bracket, while only 2% fill out only a womens bracket. Another 14% fill out a bracket for both tournaments at least some years.So, a sizable chunk of Americans are into NCAA bracketology, but whats behind the hype?Among those who fill out brackets at least some years, about 7 in 10 say a reason for their participation was for the glory of winning, the chance to win money or the fact that other people were doing it.Theyre less likely to be motivated by support for a specific school or team and in particular, to say this was a major reason for their participation.Theres certainly a financial motivation for correctly predicting the Final Four, and its hard to deny NCAA college basketball is in a betting-heavy era. More Americans canlegally bet moneyon the NCAA mens and womens basketball tournaments than in previous years, and many will place a wager on their brackets success.Does that mean Americans think the tournaments are all about wagering, or that its technically gambling to enter a friends-and-family pool with only a modest payout at stake?Most U.S. adults 56% say that if someone enters a March Madness bracket pool for money, they consider that to be gambling. About 2 in 10 say it depends on the amount of money, and another 2 in 10, roughly, say this is not gambling.Who are the March Madness bracket diehards?Men tend to make up the bulk of the regulars who fill out a bracket at least some years. Among the March Madness bracket regulars, about 6 in 10 are men, including about one-third who are men under the age of 45. These bracket regulars are less likely to be women; only about 4 in 10 are women, and theyre about evenly split between being older or younger.Those who only fill out a bracket for the mens tournament are also overwhelmingly men. About 7 in 10 people who fill out a mens bracket and not a womens bracket every year or some years are men. About 4 in 10 are men over 45, and about 3 in 10 are younger men.If you cant beat them, avoid them?Not everyone wants to risk a bracket buster and people avoiding the Madness this month are hardly alone.About 7 in 10 U.S. adults say they never fill out a mens or womens bracket. This group leans more female: About 6 in 10 bracket avoiders are women. And roughly one-third in this group are women over 45.Linley Sanders, Associated PressThe AP-NORC poll of 1,112 adults was conducted Feb. 6-10, using a sample drawn from NORCs probability-based AmeriSpeak Panel, which is designed to be representative of the U.S. population. The margin of sampling error for adults overall is plus or minus 4.1 percentage points.