IT IS as brutal as it is inevitable, as unfair as it is certain.

Come Saturday, just after 5pm when the final siren has sounded on the 2013 Grand Final, one of the coaches will have his credentials questioned.

There is always a price to pay for failing to win an AFL Grand Final.

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The AFL system, unlike many other major sports, does not allow celebratory room for teams and individuals who fail to win the match on the last Saturday in September.

You can be dominant all year, win matches you should have lost through guts and will power and be courageous in simply reaching the finals, but when you lose a Grand Final, the harshest of questions are asked.

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Alastair Clarkson and Ross Lyon know this. They have had those questions asked before, and have asked themselves the same questions.

For Clarkson, only a Hawthorn win on Saturday against Fremantle will suffice. It won't be enough for him or anyone else that he has steered a team to a third Grand Final in his nine seasons as coach.

A loss, even if it is by a small margin as it was last year, will prompt the shockingly harsh assessment of him and his team that one premiership in 2008 from a side including Buddy Franklin, Sam Mitchell and Luke Hodge is massive unders.

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For Lyon, only a Dockers win will suffice. Given the drawn Grand Final of 2010, he's coached in more Grand Finals than Clarkson, yet despite coming extraordinarily close on two occasions he's failed to win all three.

When the final siren sounded in the 2009 Grand Final, his St Kilda team was short of the mighty Geelong by six points before Max Rooke kicked a goal after time had elapsed.

When the final siren sounded the following year, his team's score was locked with Collingwood's.

No coach without a premiership to his name has gone closer to winning two Grand Finals than Lyon, but if he loses again this Saturday, even by a narrow margin, there will be no good feelings or accolades coming his way, only queries about his ability to steer a team to a flag.

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Both Clarkson and Lyon deserve the 2013 premiership. They are the best coaches in the competition. But if there's one reality that both men accept, it is that nothing in this game is simply gifted.

Clarkson has been blessed with some brilliant drafting of players, but his astute identification and acquisition of players from other clubs has been key to his club's sustained progression to high-end finals.

David Hale, Shaun Burgoyne, Josh Gibson, Brian Lake, Brent Guerra and Jack Gunston have been outstanding recruits, and the bit-part roles by Jonathan Simpkin, Kyle Cheney and Matt Spangher have also been crucial.

For Lyon, it is the ability to get total buy-in from players on his list that has seen him continually vying for the top prize.

One senses he likes having at his disposal the likes of Nathan Fyfe, Michael Walters, Chris Mayne and Luke McPharlin even more than those who trusted his every direction at St Kilda.

There is more of an X-Factor to Lyon at Fremantle than Lyon at St Kilda, and it may well be that the lessons learnt out of the hurt of 2009 and 2010 have him perfectly positioned to deal with whatever is thrown his way on Saturday.

It is unfortunate that both men will be unable to win on Saturday, and even more unfortunate that the losing coach will be subjected to soul-searching and scrutiny.

Both men will be aware of this, and accepting of it. They actually wouldn't have it any other way.

Twitter: @barrettdamian