ONE key to the Brisbane Lions causing an upset in Saturday night's "ultimate test" against the Western Bulldogs is taking advantage of their clearances, says young defender Sam Mayes. 

In Sunday's loss to Richmond, the Lions won the stoppage numbers by a considerable 43-30, but failed to translate that to the scoreboard. 

It's not a trend just yet, but the same thing happened two weeks prior against Essendon, where the Lions were +10 in that area, only to lose by 27 points. 

After the Tigers loss, coach Chris Fagan said he was unsure whether it was personnel or effort, but surmised the problems came from the Lions' lack of spread from the contest. 

Speaking on Tuesday, Mayes said it was a crucial part to get right against the fleet-footed premier. 

"Our midfield have been going quite well in the contested situations, but it's just about getting that ball and getting on the outside and being able to deliver to our young forwards," Mayes said.

"That's a focus for us, turning our clearances into goals, and hopefully we can do that this weekend." 

In Tom Rockliff, the Lions have the No.1 clearance man in the competition through the opening month. 

The vice-captain has a startling 48 next to his name, well clear of big-name midfielders Rory Sloane (33), Josh Kennedy (32) and Patrick Dangerfield (32). 

The Bulldogs are off to a 3-1 start in defence of their flag, and have overcome heavy losses in clearances against both Collingwood and North Melbourne to win.

"It's the ultimate test," Mayes said.

"It doesn't get any tougher.

"We played them in the pre-season match and did quite well then (the Lions defeated a half-strength Bulldogs).

"We'll go in with a little bit of confidence. 

"They're good in close in the contested situation, so if we can beat them at the source, we'll give ourselves a great opportunity."