THE AFL has cracked down on misbehaviour towards umpires, with players who offend against the game's officials to be sent directly to the tribunal this year.

And the league has also signalled a tougher approach to dangerous tackles in 2009, with changes to the definitions of 'impact' and 'contact'.

What is commonly termed a 'spear tackle' will now be classified as high contact, rather than body contact as in previous seasons, potentially drawing a stiffer sanction.

As well, a player who forces another into the path of a fast-moving third player may face a charge of causing high or severe impact even though the initial contact may have been classified as low or medium.

The AFL also clarified the rules on when a 25 per cent discount applies for a guilty plea when an alleged offence is referred directly to the tribunal.

The new guideline says that while the tribunal may look favourably on a guilty plea, the discount will not apply automatically,

The issue came to a head last season after Sydney Swans forward Barry Hall struck West Coast's Brent Staker and was referred directly to the tribunal.

Tribunal chairman John Hassett's recommendation at the time that the jury "strongly" consider giving Hall a 25 per cent discount may have saved him from a 10-match ban, rather than the seven he received.

AFL general manager of football operations Adrian Anderson said feedback from the 16 clubs had been valuable in making the changes, which were recommended by the AFL Tribunal Review Committee headed by former Carlton defender Andrew McKay.
 
"The AFL has examined its tribunal system each year and we will continue to do so, to see if we can continue to improve it," he said.  
 
"Last year saw the lowest number of tribunal hearings in nearly 40 years of VFL/AFL football. The changes made this year are minor, reflecting positive feedback received from players and the clubs."