THE MOST experienced umpire in the AFL, Brett Rosebury, concedes that it can be a "thankless job" when even correct decisions will only please about 50 per cent of the fans watching on, but he is still missing the energy and excitement that a big crowd brings.

Rosebury became just the third field umpire to reach the 450-game milestone last week when he officiated the Collingwood and Carlton clash but had to do it without a crowd watching on.

It is a scenario that Rosebury admits is still strange for umpires to be involved in, while he can sense the players are now trying to find ways to adapt and benefit their team.

"We don't hear the comments during a game, especially when there is a big crowd. The crowd reaction might make us aware of a big moment after it happens, but [the crowd] is usually just background noise to us," Rosebury told AFL.com.au.

"But with the reduced crowds at some games at the moment, you really do hear all of the comments, they echo through the ground and can be quite funny at times."

"When we've had no crowds in some games during this COVID-period, you notice there isn't the same intensity in the game. So now you can see the players are trying to create their own energy to give their teammates a lift like what the crowd usually gives to the game."

Rosebury is now in his 22nd season as an AFL umpire after making his debut in round 13, 2000.

He has ruled over eight Grand Finals and 36 other finals since then, and has had a close-up view of how the game has changed in the past two decades.

The 41-year-old said the most noticeable difference for umpires is in the number of tackles they now must consider in each match.

"When I started there were about 55-60 tackles a game, now the average is more like 120 and some games get 150 to 200 tackles a game," Rosebury said.

"That has made umpiring much more challenging. Every time there is a tackle the umpire has to make 5-10 snap decisions, so with more tackles there are more quick decisions to make.

"Then the players have become better at tackling and better at standing up in a tackle to try to get a handball out. It has made umpiring a lot more difficult."

The eight Grand Finals that Rosebury has officiated include three modern-day classics – in 2009 when Geelong narrowly beat St Kilda, the following year when Collingwood drew with the Saints then beat them in the replay, and 2018 when West Coast kicked a late winner against the Pies.

Rosebury said that his most memorable home and away matches include:

• Being part of Jason McCartney’s comeback match in 2003 after the North Melbourne defender was severely injured in the Bali bombings: "That was a super emotional game, you could feel that out on the field coming from the crowd";
• Umpiring the Anzac Day match in 2009 when a young David Zaharakis kicked a match-winning goal in the pouring rain: "The noise from the crowd was just incredible".

Despite passing the 450-game milestone Rosebury isn't quite ready to commit to overtaking the bigger tallies reached by Hayden Kennedy (495) and field umpire games record-holder Shane McInerney (502).

"You don't really umpire for milestones or game numbers, it's everyone else who is pushing me to get to 500," Rosebury said with a laugh.

"Even though it can be a thankless job at times, my body is good, my mind is good and my spirit is good. As long as those things are in the right space and I feel like I'm umpiring at a high level then I'll keep doing it."