IT'S BEEN 144 days since Richmond lifted the 2020 premiership. 

Here's what's happened since if you've been living under a rock. 

ON THE FIELD

- Quarter lengths have returned to 20 minutes plus time-on just as they were in 2019. Quarters were slashed to 16 minutes plus time-on for the 2020 season only. 

- Each club will be allowed to make 75 interchanges per game in 2021, down from 90 permitted in 2020.

- A new man on the mark rule has been introduced in order to speed up ball movement. The defending player won't be able to move laterally on the mark and will be forced to become a statue when the umpire calls him to 'stand'. Any infringement before 'play on' is called will result in a 50m penalty.

- Following a behind, the player on the mark defending the kick-in has been pushed back by five metres. Last year the defending player was required to be 10m back from the goalsquare, this year it's been extended to 15m. 

- The AFL has introduced a medical substitute for all games this season. From round one, all clubs will be able use 23 players for each game instead of the regular 22, but that extra 23rd player will only be able to take the field after club doctors have assessed an injured or concussed player as 'medically unfit' to continue in the match.

THE FIXTURE

- After a 17-game home and away season in 2020, the 2021 Toyota AFL Premiership Season returns to the traditional 22 matches for each club. 

- The entire fixture of match-ups has been locked in with only the first six rounds of timeslots announced before the start of the season. The rest of the season will be released in blocks throughout the year. 

- The Toyota AFL Grand Final will return to a traditional 2.30pm start on Saturday, September 25 at the MCG after last year saw the decider played at night at the Gabba.

- Team announcements will continue the day before each game at 6.20pm AEDT 

CONCUSSION RULES

- The AFL has doubled the mandatory break for a concussion from six days to a minimum 12-day break. All players who suffer a concussion will miss at least one match under standard fixturing, meaning if a player is concussed in a preliminary final, they'll miss the Grand Final. 

CROWD FIGURES

- Football will return to Victoria with 50 per cent crowds at the MCG (50,000), Marvel Stadium (28,961) and GMHBA Stadium (18,546) from round one.

- The Adelaide Oval (40,000) and Perth's Optus Stadium (45,000) will be able to house 75 per cent crowds from round one.

- The SCG (36,000) and Giants Stadium (18,000) will also be able to operate at 75 per cent to start the season. 

- There are no current restrictions on crowd limits at the Gabba or Metricon Stadium in Queensland.

- All venues will be subject to change depending on individual state rules.  

PLAYER MOVEMENT

- Adam Treloar (Western Bulldogs), Jeremy Cameron (Geelong), Zac Williams (Carlton), Joe Daniher (Brisbane), Jesse Hogan (GWS) and Ben Brown (Melbourne) were among the big names to find new homes during the post-season player movement window.

- A total of 59 players were selected in the 2020 NAB AFL Draft, with Adelaide using the No.1 pick (Jamarra Ugle-Hagan) to place a bid for the first time. Ugle-Hagan joined the Dogs as a member of their Next Generation Academy. Former Giant Jackson Hately joined the Crows as the sole selection in the Pre-Season Draft, while 26 players won spots as rookies.

- Tom Scully (Hawthorn), Sam Lloyd (Western Bulldogs) and Ross McQuillan (Essendon) announced their retirements post-season. 

- Sydney sacked young forward Elijah Taylor in November after he pleaded guilty to an assault charge.

- Twelve players were handed career lifelines in the Pre-Season Supplemental Selection Period (SSP) which ran from January-March.

- The Mid-Season Rookie Draft is currently scheduled for June. 

LEADERSHIP CHANGES

- Ben McEvoy replaced the retired Ben Stratton as Hawthorn captain.

- Jack Steele was elevated to co-captain at St Kilda alongside 2020 skipper Jarryn Geary. 

OFF-FIELD MOVES

- David Noble was appointed North Melbourne coach in November, replacing Rhyce Shaw who later joined Gold Coast as a development coach.

- Collingwood president Eddie McGuire departed his post in February after a 22-year tenure with Mark Korda and Peter Murphy announced joint vice-presidents. Craig Drummond replaced the outgoing Colin Carter as Geelong president. 

- Tim Silvers (Adelaide) and Matthew Richardson (Port Adelaide) were unveiled as new chief executives

- Danny Daly (Brisbane), Alan Richardson (Melbourne), Graham Wright (Collingwood), Rob McCartney (Hawthorn) and Josh Mahoney (Essendon) took positions as head of football around the competition. 

CAP SQUEEZES

- The salary cap dropped by nine per cent from 2020 into 2021 with each player mandated to take a minimum of 3.5 per cent cut. The remainder was made up of a reduction in list sizes, with players who re-signed after the 2020 contract freeze which was put in place during the lockdown (and committed to a bigger cut) able to move their difference into future seasons. 

- A host of clubs introduced uniform cuts for their whole playing list including Richmond (five per cent), West Coast (seven) and St Kilda (seven). 

- Maximum list sizes have dropped from 47 players in 2020 to 44 in 2021, inclusive of two Category B rookies (players from alternative backgrounds such as Next Generation Academies or non-football pathways). Minimum list sizes now sit at 37.

- Category B rookies are now eligible for senior selection without the need to be upgraded to the senior list.

- Football department spending per club (soft cap) has dropped from more than $9 million to a tick over $6 million. It has resulted in a reduction in coaches at a number of clubs across the competition. 

PRE-SEASON STRUCTURE

- The length of the pre-season was dramatically cut for senior players. First-to-fourth-year players completed two weeks of training before Christmas with all others required back only post-Christmas for the first time. 

- The official pre-season competition – the AAMI Community Series – was cut from two matches per club to one.  

SECOND-TIER COMPETITION

- Following the disbandment of the NEAFL, 22 clubs will form the new VFL and East Coast Second-Tier Competition. It will be made up of eight standalone clubs without an alignment to an AFL team. The 16-game season will begin on April 17.