In a 4-5-1 formation, the full back hits a very long cross-field pass to the winger on the opposite side, who would head the ball to either one of the central midfielders or to the striker.
The inventor of this kind of passing is the Norwegian head coach Egil "Drillo" Olsen, who was the side's coach between 1990–98, retiring after the World Cup 1998. "Drillo" has now returned to the job to take Norway to the European Championship 2012.
The genius with the Flo pass is the fact that the two players with best heading and aerial abilities in a back four is usually playing as the centre backs/half backs. Jostein Flo was a massive threat in the air but the fact that he played on the right winger, meant that he only had to face the left back, who was usually weaker than the central defenders, in an air clash. This increased the possibility of winning the ball, and the side were able to build up the attack from here.
Another advantage with this kind of play is that a technically limited football nation as Norway, with only about 5 million people and lots of snow in winter time limiting the possibilities to practice dribbling skills and other technical movements, can play on their strengths rather than their weaknesses. The only thing you need to play a Flo pass is a back with a good crossing ability, usually performed by the former Liverpool left back Stig Inge Bjørnebye, and a player with good aerial abilities, usually performed by Jostein Flo. You don't need to dribble, pass and show off your skills to get the ball to the opposite side's goal in a technical and skillful way. Just give the ball to the left back (or right, playing the ball to the left winger) and crossing the ball in a Flo pass. This moves the ball very quickly, and is also able to surprise your opponent out of balance in a counterattack.
This kind of simple and effective way of play sent the traditionally weak football nation Norway to the runner-up spot at the FIFA ranking in 1997, only second to four (now five) time FIFA World Cup winner Brazil. As well, Norway is the only national team who have never lost to the Seleção. Norway won 4-2 in 1997 in a friendly match, sensationally 2-1 in the FIFA World Cup 1998 final match of the group stage (Norway advanced to the last 16, but lost 0-1 to Italy) and a friendly draw (1-1) in 2007. The same result as the two teams played in 1988. With the tactic Norway won against traditionally strong football nations like England, winning 2-1 in 1981.