His idea was that umpires "throw the whistle away" as the game nears its end.
He's right about the free-kick tallies. According to Champion Data, the number of free kicks scales down as the game progresses.
This was true in round five when you look at the figures over the seven games.
Almost 32 per cent of a game's free kicks were paid in the first quarter. About 25 per cent were paid in the second, 23 per cent in the third and 21 per cent in the final quarter.
It's also true when you consider the figures over the five rounds this season: percentages of 29, 25, 24 and 21.
Tellingly, the figures are pretty much unchanged when you look at results for the whole of last season and then you look at the season of a decade before, in 2000.
In both cases, the percentages of free kicks paid from the first to last quarters are about 28 per cent, 25, 23 and 22.
Jeff Gieschen, the AFL umpires' director, looked into the issue a decade ago after watching a Collingwood and Adelaide game in which no free kicks were paid in the last quarter.
He said it's true the number of free kicks generally scales down as a game progresses. This is because players are eager to set the tone at the beginning of a game, laying tackles, breaking tags and throwing themselves recklessly into contests.
The umpires set their own tone by coming down hard early on holding-the-ball infringements and tackling infringements. The idea is to guard against stoppages.
The players figure out just how much the rules will be applied. As the game progresses, they become more and more watchful about giving away free kicks.
"At the start, the players are souped up, their adrenalin is high," Gieschen said. "By and large, as the game wears on the players work out how the umpires are adjudicating."
And what of Roos's other point, that the umpires throw their whistles away late in a game?
If round five is a guide, the answer is no.
A deliberate out-of-bounds penalty was paid against the Gold Coast Suns' Jarrod Harbrow deep in the Port Adelaide forward line late in their close game.
Richmond's Dustin Martin received a free kick when North Melbourne midfielder Andrew Swallow put his knee in his ribs late in their close game.
Gieschen said both decisions were correct. They were examples of umpires calling the play as they see it.
Surely, however, it's human nature for an umpire to hesitate about paying a free kick near goal as a close match nears the final siren.
There are no figures on that. It remains another glorious uncertainty of the game.
Round 5, 2011
Q1: 90 frees, 31.6%
Q2: 71, 24.9
Q3 65, 22.8
Q4 59, 20.7
Rounds 1-5, 2001
Q1: 482 frees, 29.4%
Q2: 414, 25.2%
Q3: 400, 24.4%
Q4: 345, 21.0%
Season 2010
Q1: 2065 frees, 28.6%
Q2: 1838, 25.5%
Q3: 1763, 24.5
Q4: 1542, 21.4
Season 2000
Q1: 1605 frees, 28.3%
Q2: 1458, 25.7%
Q3: 1329, 23.4%
Q4: 1284, 22.6%
