Monday night football has turned into the Bermuda Triangle for favourites with even the hottest NRL teams coming unstuck on Monday nights as underdog after underdog provides upset after upset. TV viewers might love Monday night football; punters are becoming distinctly less keen.

Weird happenings have been the order of the night most Monday's this season. In 21 Monday matches, the outsider in betting at TAB Sportsbet have won 13 matches outright. That is an astonishing run for the puppies.

Last Monday, the Newcastle Knights defeated Manly as a 7.5-point outsider. The Knights entered the match coming off a loss to the last-placed Cowboys and a 52-18 flogging at the hands of Canberra. Manly were cruising after big wins over Cronulla and the top-four Wests Tigers. Newcastle jumped to a 24-4 half-time lead and cruised to a 32-14 victory. Punters could have taken $3.00 about Newcastle claiming the two points.

That loss was hardly the biggest Monday night shock of the season.

The Gold Coast Titans shocked Manly at Brookvale Oval as an 8.5-point outsider. The Titans had never got within 14 points against Manly at Fortress Brookie. The Titans won 24-22.

North Queensland have won only one road match all season. That came on a Monday night in May when the Cowboys, with a 2-6 record at the time, blew away the Roosters, the same Rooster team who are currently third on the ladder, with a 32-14 win at Sydney Football Stadium as an 8.5-point dog. The Cowboys had lost four straight heading into the match. They lost three straight after. It was the Roosters first home loss of 2010.

Penrith shocked the Dragons at Kogarah when missing Origin stars Luke Lewis, Michael Jennings, Petero Civoniceva and Michael Gordon as well as key halfback Luke Walsh as a 7.5-point underdog. Penrith then lost three straight.

Home underdogs have won three of their last four on Monday night. Since the calendar was flipped to April, the underdog has won 12 of 13 matches when Cowboys games are excluded. The last five favourites to be backed heavily enough so that the price of the line moves below $1.90 have lost.

Every trend and stat points to the same neon sign: BET THE UNDERDOG ON MONDAY NIGHT. Bet them straight out, bet them at the line. Disregard instinct, form and statistics. Playing the underdog is the top betting trend in the NRL this year.

Canberra host Penrith next Monday, and will probably start as marginal outsider. But the home-side underdogs are on a 3-0 streak on Monday nights, so the omens are there for another upset.

Theories on why the underdog is so strong on a Monday night are plentiful. Favourites tend to be shorter than they would at any other point over the weekend because punters like to chase favourites when behind and Monday night is for chasing. Teams playing Monday get to see how the competition plays out and the underdog tends to be more desperate to stay in touch knowing what a win and a loss will do for their ladder standing. Teams lift for a match that increasingly is becoming the most prestigious of the round in terms of build-up. Crowds for Monday night matches tend to be below average and as such the home-ground advantage tends to be diminished.

For punters though, it isn't about the why. It is about the fact that underdogs have an undeniably brilliant record on Monday night. That nugget of gold should prove the punters best pal for the remainder of the season.

(Nick Tedeschi is a rugby league fan, punter, freelance writer and Back Page Lead contributor.)