ENGLISH RFU
Along with the hooker, the loose-head and tight-head props make up what is known as the front row, which refers to their position in the scrum.

It takes a special breed of player to be effective in the front row. With the rest of their pack behind them driving forward, the front row is the epicentre of the scrum and the point where the two packs collide, literally head on.

To be successful, both props must be extremely strong in the neck, shoulders, upper body and legs, and they should relish head-to-head competition. England and British Lions tight-head Phil Vickery's taste in tattoos sums up the prop mentality. The 19st 9lb Vickery has oriental writing on one arm that translates roughly as "I will fight you to the death."

While stopping their side of the scrum from moving backwards, the props also support the hooker's body weight, allowing him or her to see and strike the ball when it is put into the scrum. In the lineout, props should be able to support or lift the jumper to prevent the opposition winning the ball.

Away from set pieces, props help to secure the ball when a player has been tackled, so it helps if they can combine their power with a degree of mobility. You’ll also often see them used as battering rams in attack, receiving short passes after a ruck or maul and hitting the opposition defence at pace in an attempt to occupy the defenders and make space for their own backs.

Key Abilities
Strength, power, bravery, mobility

JASON LEONARD
"A prop's main role is to scrummage, support in the line-out, tackle and hit the rucks and mauls. No matter how fast and powerful the game becomes, a prop will always be a prop.

The difference nowadays is that props also have to be able to catch, time a pass to put team-mates into space and run. Many top props are now very powerful runners and you may even see the odd sidestep.

The tight-head prop is very much the fulcrum. He anchors the whole scrum and is destructive in a negative sense. He will be trying to put the opposition loose-head under pressure."

England's Andrew Sheridan (pictured) is a loose-head prop

"The primary role of the loose-head, on the other hand, is to look after the hooker so he can get a clean strike at the ball, but these days loose-heads have to be destructive too.

The tight-head plays on the right of the front-row and mainly uses the right-hand side of his body, whereas the loose-head's left side dominates. Because of this it is fairly rare to find someone who can excel at both.

To be a good prop, you've really got to enjoy the position - it's not everyone's cup of tea, putting your head where it hurts. It's possibly the only true position on the field where you actually have a one-on-one with your opposite number and I relished that aspect of it. You need to love that confrontational challenge to get the most out of it.

A perfect modern prop is a fantastic scrummager, great in the line-out, has good hands, contributes all around the park and regularly tops the tackle count."