What is an AFL ruckman?

— -- A feature of Australia's indigenous sport, Australian rules football, is that it is a game for most shapes and sizes.

From nuggety runners -- Western Bulldogs midfielder Caleb Daniel is only 168cm tall -- to physically imposing key position players, such as 201cm Essendon full-forward Joe Daniher, the game offers opportunities to anyone who is talented and fit enough.

However, ruckmen are the game's giants -- with Collingwood's Mason Cox the tallest in the Australian Football League at 211.4cm.

Cox, a former college basketball player in the US, will make his debut for the Magpies against Essendon on Anzac Day, which is the biggest game of the AFL year outside the post-season finals

Generally the tallest players on each team, ruckmen compete for the ball at the centre bounces that begin matches or re-start play after a goal has been kicked (think a more physical basketball tip off), as well as grappling with their opponents at boundary throw-ins around the ground.

It's a physically demanding position. Ruckmen must run up and down the ground all match, and jump and crash into each other at full force throughout a game.

Often, they will cover between 7.5-12.5 miles (12-20 km) in a game - involving high-intensity sprints interspersed with jogging and walking. That's in addition to the physical contact of regular tackling and bumping.

It's a pivotal position for all teams, with ruckmen expected to set the physical tone for his side.

That's not to say ruckmen are just human-shaped battering rams. They must use their nous and skill to direct ruck taps to smaller teammates, who can then move the ball forward to create scoring opportunities.

They must also run forward to provide attacking options, or help out in defence, and often do it all without any support -- teams usually select onlyone ruckman per match.