Fading the San Francisco 49ers has been the most popular NFL bet this offseason at one Las Vegas sportsbook.

Sportsbook operator CG Technology posted season win totals on all 32 teams in mid-February. San Francisco opened at 8.5 wins and attracted immediate heavy action on the under from respected bettors. According to vice president of race and sports Jason Simbal, the book took six bets of $1,000 or more on the under. CG Technology didn't take a bet of any significance on the San Fran over until mid-April, after the win total had been trimmed to 8.

The types of bettors? "All under, all smart guys," Simbal said.

It's not hard to figure out what's behind the anti-Niners sentiment. Coach Jim Harbaugh bolted for Michigan in December. Veteran workhorse running back Frank Gore signed with the Indianapolis Colts, among other notable free-agent departures and starting linebackers Patrick Willis and Chris Borland announced their retirement in March.

Overall, with the regular-season schedule not being released until Tuesday night (8 p.m. ET, ESPN), the action on the win totals has been mostly small, public wagers. The 49ers are the exception. The average size of bet on the San Francisco under was $200.

"The average size on the other teams is like $30," Simbal said.

The Colts also attracted lopsided action. Their win total opened at 9.5, but was moved up to 10, after 35 of the first 36 bets that came in were on the over.

The Seattle Seahawks, the consensus Super Bowl favorites in Las Vegas, have the highest win total at 11. The defending champion New England Patriots are next at 10.5, followed by the Green Bay Packers and Colts at 10. The Oakland Raiders, at 4.5, have the lowest win total. Simbal said bettors were supporting the overs on the Arizona Cardinals (8), New York Giants (8), Minnesota Vikings (6.5) and Miami Dolphins (8).

CG Technology will post point spreads for games in Weeks 1 through 16 in late May.

The Westgate Las Vegas SuperBook will post lines for every Week 1 game at 7 p.m. PT, Tuesday.