AFL Prediction & Analysis

HPN now on Squiggle

HPNMost computer models of AFL have no awareness of who’s actually playing in either team. They rate the strength of competing clubs as an entity, rather than what they really are: a collection of moving parts, some of whom move a lot better than others.

Earlier this year, HPN, the artist formerly known as Hurling People Now, launched PERT, a tipping model that draws on the ratings of the actual players, as determined by the PAV system.

It’s early days, but PERT looks likely to add a fascinating new dimension to model-based tipping, and is definitely worth keeping an eye on.

Because PERT tips depend on the announced teams, they come out later in the week and can alter based on last-minute personnel changes.

I’m delighted to have HPN on board and PERT tips are now integrated into Squiggle dials and the leaderboard!

Swinburne University joins Squiggle

SwinburneToday I’m thrilled to welcome Swinburne University’s famous computer model! Running continuously since 1981, this is the country’s oldest and best-known AFL tipping model.

The man behind the model, Professor Stephen Clarke, has kindly agreed to join in, and Swinburne is now included in the models leaderboard and tips pages.

Due to confidentiality requirements, Swinburne margin and probability tips are embargoed until the completion of each game: until that point, only the name of the tipped team is displayed.

It’s very exciting to have the great grandaddy of AFL computer models on board.

Swinburne is off to a solid start this year, too, shooting straight to #1 on the Squiggle leaderboard! A good challenge for the rest of us.

Dangerous Extrapolations

I’ve now fixed the code that dumbly extrapolated out scoring shots of live matches, the problems with which were kindly highlighted by North Melbourne and St Kilda last week.

Squiggle would now project those 2nd-quarter scores of 2.9 (21) – 2.7 (19) out to 8.16 (64) – 10.15 (75)… which is more plausible. Although still not very close to the actual final scores of 13.17 (95) – 5.13 (43).

More Model Updates for 2018

Got some more updates ahead of season 2018:

  1. Pre-season Tracking: We had something resembling a normal preseason this year, so Squiggle is using those results in its calculations for the season ahead.
     
  2. Round-based Sensitivity: Squiggle is now more sensitive in the early rounds and in finals, to better capture the important signalling of surprising results at these times. In particular, an unexpected Round 1 result can cause a team to move a very long way.
     
  3. Goal-kicking Accuracy: As flagged last year, since goalkicking accuracy seems to be non-reproducible — teams that are highly accurate one week aren’t more likely to be highly accurate the next — Squiggle will interpret a scoreline like 13.20 as a team that was unlucky to not win by more, and thus will rate them more highly, while a scoreline like 12.3 will be interpreted as a team that got closer than they probably deserved.
     
  4. Home Ground Advantage: Gone is the practice of assigning 12 points of home advantage to interstate hosts and ignoring everything else! Squiggle now calculates HGA based on relative ground & state familiarity: It scores each team on how many times they’ve played at the same venue and (less significantly) in the same state over recent years, and assigns HGA points based on how lopsided the numbers are. So at venues where both teams have played fairly often, ground familiarity is balanced and there’s not much HGA, if any. At venues where one teams plays a lot and the other team rarely even visits the state, HGA is high.

The main difference in practice is better modelling of Geelong in Melbourne, along with uncommon situations like Melbourne playing in the Northern Territory. For example, for the Round 1 Melbourne vs Geelong game at the MCG, under the old model Squiggle would give Melbourne 12 points of HGA, but under the new model, it’s only 2.5 points, due to the Cats’ fairly good familiarity with that ground.

Actually here are the current HGA values for all R1 matches:

  • Richmond +1.1 vs Carlton @ MCG
  • Essendon +7.9 vs Adelaide @ Docklands
  • St. Kilda +7.6 vs Brisbane @ Docklands
  • Port Adelaide +10.0 vs Fremantle @ Adelaide Oval
  • Gold Coast +10.3 vs North Melbourne @ Cazalys
  • Hawthorn -1.0 vs Collingwood @ MCG
  • GWS +9.0 vs Bulldogs @ UNSW Canberra
  • Melbourne +2.5 vs Geelong @ MCG
  • West Coast +10.9 vs Sydney @ Perth Stadium

Hawthorn are the only home team to have negative HGA. West Coast still get a bunch of HGA despite playing on a brand new ground due to the state-based numbers.

Fixture Analysis 2018: Home Ground Advantage

Home ground advantage is often overlooked, underrated, or just plain cocked up in fixture analysis. Which is strange, because it’s one of the most reliable predictors. We don’t know whether a team’s double-up opponents will become tougher or weaker in 2018, but we do know it’s always better to play interstate opponents at home.

In theory, all teams should face a balanced fixture, and travel to face interstate opponents the same number of times as they host them at home. But in practice, this doesn’t happen. Some teams enjoy home games against interstate opponents while staying local for their away games, and sometimes teams play “away” games at their home ground, with their opponents forced to travel to them.

This is home ground advantage fixture bias. The AFL does a pretty good job of managing it, but each year there are imbalances, with some sides coming out better than others, playing more games at favourable venues than unfavourable ones. While it’s not the only factor in fixture difficulty, I think it’s important enough to take a closer look. So in this post, I analyze every team’s fixture and discuss why it’s good, bad, or break-even.

Favourabity is the net total of points a team receives from home ground advantage during the season. Throughout 2018, Hawthorn will receive a net benefit of a little over five goals from home ground advantage, while the Suns will be penalized almost the same amount.

Favourability is calculated by classifying each game as one of three types:

Interstate advantage (+10): a team hosts an opponent who travels from interstate. This includes Geelong home games against Melbourne-based sides, given the Cats’ superb record there.

Local advantage (+1): a team hosts an opponent located in the same city.

Limited advantage (+5): a few specific cases: a Melbourne-based team hosting Geelong at the MCG or Docklands, Hawthorn or North Melbourne hosting a Melbourne-based team in Tasmania, and Melbourne hosting a Melbourne-based team in Darwin.

These numbers are, I think, generally accepted in AFL analytics. That is, it’s commonly agreed that interstate home advantage is worth somewhere in the realm of 10 points, while the advantage of playing a local team in your own city is almost negligible. If you want to adjust them a couple of points either way, though, I won’t quibble.

HAWTHORN

The Hawks travel to face interstate opponents four times, the fewest in the league, while interstate teams have to travel to face them six times, a league-high two-game discrepancy in their favour. On top of that, they play Geelong at home, which is worth +5, and they also have an “away” game against the Cats at the same venue. This effectively gives the Hawks 12 home games for the year, eight of which are against non-Melbourne sides.

That’s a remarkable number, only just short of the ten games that non-Victorian sides typically receive. In fact, it’s the same number as Gold Coast, who have to travel seven more times than the Hawks do to face interstate opponents.

And that’s not all: Hawthorn also take St. Kilda to Tasmania, which turns a +1 game into +5. The net result is a 32 point bonus over the course of the season.

+10 GAMES (x6)
R8: Sydney @ M.C.G. (VIC)
R10: West Coast @ Docklands (VIC)
R11: Port Adelaide @ University of Tasmania Stadium (TAS)
R13: Adelaide @ M.C.G. (VIC)
R14: Gold Coast @ University of Tasmania Stadium (TAS)
R17: Brisbane Lions @ University of Tasmania Stadium (TAS)
+5 GAMES (x3)
R2: Geelong @ M.C.G. (VIC)
R6: St Kilda @ University of Tasmania Stadium (TAS)
R21: Geelong @ M.C.G. (VIC)
+1 GAMES (x3)
R1: Collingwood @ M.C.G. (VIC)
R4: Melbourne @ M.C.G. (VIC)
R20: Essendon @ M.C.G. (VIC)
-1 GAMES (x6)
R3: Richmond @ M.C.G. (VIC)
R5: North Melbourne @ Docklands (VIC)
R7: Essendon @ M.C.G. (VIC)
R16: Western Bulldogs @ Docklands (VIC)
R18: Carlton @ Docklands (VIC)
R22: St Kilda @ Docklands (VIC)
-10 GAMES (x4)
R9: Brisbane Lions @ Gabba (QLD)
R15: Greater Western Sydney @ Sydney Showground (NSW)
R19: Fremantle @ Optus Stadium (WA)
R23: Sydney @ S.C.G. (NSW)

FREMANTLE

Fremantle are the lucky recipient of an “away” game against Gold Coast in Perth due to the unavailability of Carrara due to Commonwealth Games renovations. This transforms the game from -10 to +10, giving the Dockers 11 games with interstate advantage in their favour and only nine against.

+10 GAMES (x11)
R2: Essendon @ Optus Stadium (WA)
R3: Gold Coast @ Optus Stadium (WA)
R5: Western Bulldogs @ Optus Stadium (WA)
R8: St Kilda @ Optus Stadium (WA)
R10: North Melbourne @ Optus Stadium (WA)
R12: Adelaide @ Optus Stadium (WA)
R15: Brisbane Lions @ Optus Stadium (WA)
R17: Port Adelaide @ Optus Stadium (WA)
R19: Hawthorn @ Optus Stadium (WA)
R21: Carlton @ Optus Stadium (WA)
R23: Collingwood @ Optus Stadium (WA)
+1 GAMES (x1)
R6: West Coast @ Optus Stadium (WA)
-1 GAMES (x1)
R20: West Coast @ Optus Stadium (WA)
-10 GAMES (x9)
R1: Port Adelaide @ Adelaide Oval (SA)
R4: Greater Western Sydney @ UNSW Canberra Oval (ACT)
R7: Richmond @ M.C.G. (VIC)
R9: Sydney @ S.C.G. (NSW)
R11: Collingwood @ M.C.G. (VIC)
R13: Carlton @ Docklands (VIC)
R16: Melbourne @ Marrara Oval (NT)
R18: Essendon @ Docklands (VIC)
R22: Geelong @ GMHBA Stadium (Gee)

PORT ADELAIDE

Port Adelaide’s otherwise balanced fixture is tilted in their favour by playing Gold Coast at a neutral venue (China) instead of at the Suns’ home ground.

+10 GAMES (x10)
R1: Fremantle @ Adelaide Oval (SA)
R3: Brisbane Lions @ Adelaide Oval (SA)
R5: Geelong @ Adelaide Oval (SA)
R12: Richmond @ Adelaide Oval (SA)
R13: Western Bulldogs @ Adelaide Oval (SA)
R14: Melbourne @ Adelaide Oval (SA)
R16: St Kilda @ Adelaide Oval (SA)
R18: Greater Western Sydney @ Adelaide Oval (SA)
R21: West Coast @ Adelaide Oval (SA)
R23: Essendon @ Adelaide Oval (SA)
+1 GAMES (x1)
R8: Adelaide @ Adelaide Oval (SA)
-1 GAMES (x2)
R9: Gold Coast @ Adelaide Arena at Jiangwan Stadium (CHI)
R20: Adelaide @ Adelaide Oval (SA)
-10 GAMES (x9)
R2: Sydney @ S.C.G. (NSW)
R4: Essendon @ Docklands (VIC)
R6: North Melbourne @ Docklands (VIC)
R7: West Coast @ Optus Stadium (WA)
R11: Hawthorn @ University of Tasmania Stadium (TAS)
R15: Carlton @ M.C.G. (VIC)
R17: Fremantle @ Optus Stadium (WA)
R19: Western Bulldogs @ Mars Stadium (VIC)
R22: Collingwood @ M.C.G. (VIC)

COLLINGWOOD

Collingwood’s fixture is mostly balanced, with five interstate home games and five interstate away, but they benefit from playing Geelong at the MCG.

+10 GAMES (x5)
R2: Greater Western Sydney @ M.C.G. (VIC)
R11: Fremantle @ M.C.G. (VIC)
R17: West Coast @ M.C.G. (VIC)
R21: Brisbane Lions @ Docklands (VIC)
R22: Port Adelaide @ M.C.G. (VIC)
+5 GAMES (x1)
R8: Geelong @ M.C.G. (VIC)
+1 GAMES (x5)
R5: Essendon @ M.C.G. (VIC)
R6: Richmond @ M.C.G. (VIC)
R10: Western Bulldogs @ Docklands (VIC)
R14: Carlton @ M.C.G. (VIC)
R18: North Melbourne @ M.C.G. (VIC)
-1 GAMES (x6)
R1: Hawthorn @ M.C.G. (VIC)
R3: Carlton @ M.C.G. (VIC)
R9: St Kilda @ Docklands (VIC)
R12: Melbourne @ M.C.G. (VIC)
R16: Essendon @ M.C.G. (VIC)
R19: Richmond @ M.C.G. (VIC)
-10 GAMES (x5)
R4: Adelaide @ Adelaide Oval (SA)
R7: Brisbane Lions @ Gabba (QLD)
R15: Gold Coast @ Carrara (QLD)
R20: Sydney @ S.C.G. (NSW)
R23: Fremantle @ Optus Stadium (WA)

WESTERN BULLDOGS

The Bulldogs’ fixture is mostly balanced, with five interstate home games and five interstate away,
but they also have a game against Geelong at the Docklands, a venue in their favour.

+10 GAMES (x5)
R2: West Coast @ Docklands (VIC)
R4: Sydney @ Docklands (VIC)
R7: Gold Coast @ Mars Stadium (VIC)
R8: Brisbane Lions @ Docklands (VIC)
R19: Port Adelaide @ Mars Stadium (VIC)
+5 GAMES (x1)
R15: Geelong @ Docklands (VIC)
+1 GAMES (x5)
R3: Essendon @ Docklands (VIC)
R6: Carlton @ Docklands (VIC)
R11: Melbourne @ Docklands (VIC)
R14: North Melbourne @ Docklands (VIC)
R16: Hawthorn @ Docklands (VIC)
-1 GAMES (x6)
R10: Collingwood @ Docklands (VIC)
R17: Melbourne @ M.C.G. (VIC)
R20: St Kilda @ Docklands (VIC)
R21: North Melbourne @ Docklands (VIC)
R22: Carlton @ Docklands (VIC)
R23: Richmond @ M.C.G. (VIC)
-10 GAMES (x5)
R1: Greater Western Sydney @ UNSW Canberra Oval (ACT)
R5: Fremantle @ Optus Stadium (WA)
R9: Adelaide @ Adelaide Oval (SA)
R13: Port Adelaide @ Adelaide Oval (SA)
R18: West Coast @ Optus Stadium (WA)

NORTH MELBOURNE

Like Hawthorn, North benefit from dragging a Melbourne-based team to Tasmania, turning what should be a +1 game against the Saints into +5. Otherwise their fixture is balanced.

+10 GAMES (x6)
R6: Port Adelaide @ Docklands (VIC)
R9: Greater Western Sydney @ Bellerive Oval (TAS)
R11: Brisbane Lions @ Docklands (VIC)
R16: Gold Coast @ Docklands (VIC)
R17: Sydney @ Docklands (VIC)
R19: West Coast @ Bellerive Oval (TAS)
+5 GAMES (x1)
R4: Carlton @ Bellerive Oval (TAS)
+1 GAMES (x4)
R2: St Kilda @ Docklands (VIC)
R5: Hawthorn @ Docklands (VIC)
R8: Richmond @ Docklands (VIC)
R21: Western Bulldogs @ Docklands (VIC)
-1 GAMES (x5)
R3: Melbourne @ M.C.G. (VIC)
R14: Western Bulldogs @ Docklands (VIC)
R15: Essendon @ Docklands (VIC)
R18: Collingwood @ M.C.G. (VIC)
R23: St Kilda @ Docklands (VIC)
-10 GAMES (x6)
R1: Gold Coast @ Cazaly’s Stadium (QLD)
R7: Sydney @ S.C.G. (NSW)
R10: Fremantle @ Optus Stadium (WA)
R12: Geelong @ GMHBA Stadium (Gee)
R20: Brisbane Lions @ Gabba (QLD)
R22: Adelaide @ Adelaide Oval (SA)

RICHMOND

Richmond host interstate teams only four times, equal fewest in the league, while having to travel interstate themselves five times. But they more than make up for this by receiving two games against Geelong at the MCG, one of which is a nominal away game.

+10 GAMES (x4)
R4: Brisbane Lions @ M.C.G. (VIC)
R7: Fremantle @ M.C.G. (VIC)
R15: Sydney @ Docklands (VIC)
R16: Adelaide @ M.C.G. (VIC)
+5 GAMES (x2)
R13: Geelong @ M.C.G. (VIC)
R20: Geelong @ M.C.G. (VIC)
+1 GAMES (x6)
R1: Carlton @ M.C.G. (VIC)
R3: Hawthorn @ M.C.G. (VIC)
R10: St Kilda @ M.C.G. (VIC)
R19: Collingwood @ M.C.G. (VIC)
R22: Essendon @ M.C.G. (VIC)
R23: Western Bulldogs @ M.C.G. (VIC)
-1 GAMES (x5)
R5: Melbourne @ M.C.G. (VIC)
R6: Collingwood @ M.C.G. (VIC)
R8: North Melbourne @ Docklands (VIC)
R11: Essendon @ M.C.G. (VIC)
R18: St Kilda @ Docklands (VIC)
-10 GAMES (x5)
R2: Adelaide @ Adelaide Oval (SA)
R9: West Coast @ Optus Stadium (WA)
R12: Port Adelaide @ Adelaide Oval (SA)
R17: Greater Western Sydney @ Sydney Showground (NSW)
R21: Gold Coast @ Carrara (QLD)

GEELONG

Geelong play just nine games at their true home and 13 games away, which is an enormous discrepancy. But since their Kardinia games are all rated +10 while their MCG and Docklands games are only -5, they come out even on balance.

+10 GAMES (x9)
R4: St Kilda @ GMHBA Stadium (Gee)
R6: Sydney @ GMHBA Stadium (Gee)
R7: Greater Western Sydney @ GMHBA Stadium (Gee)
R10: Carlton @ GMHBA Stadium (Gee)
R12: North Melbourne @ GMHBA Stadium (Gee)
R18: Melbourne @ GMHBA Stadium (Gee)
R19: Brisbane Lions @ GMHBA Stadium (Gee)
R22: Fremantle @ GMHBA Stadium (Gee)
R23: Gold Coast @ GMHBA Stadium (Gee)
-5 GAMES (x8)
R1: Melbourne @ M.C.G. (VIC)
R2: Hawthorn @ M.C.G. (VIC)
R8: Collingwood @ M.C.G. (VIC)
R9: Essendon @ M.C.G. (VIC)
R13: Richmond @ M.C.G. (VIC)
R15: Western Bulldogs @ Docklands (VIC)
R20: Richmond @ M.C.G. (VIC)
R21: Hawthorn @ M.C.G. (VIC)
-10 GAMES (x5)
R3: West Coast @ Optus Stadium (WA)
R5: Port Adelaide @ Adelaide Oval (SA)
R11: Gold Coast @ Carrara (QLD)
R16: Sydney @ S.C.G. (NSW)
R17: Adelaide @ Adelaide Oval (SA)

SYDNEY

Sydney’s fixture is neatly balanced with 10 interstate games away, 10 at home, and 2 local bridge battles or whatever they’re called.

+10 GAMES (x10)
R2: Port Adelaide @ S.C.G. (NSW)
R5: Adelaide @ S.C.G. (NSW)
R7: North Melbourne @ S.C.G. (NSW)
R9: Fremantle @ S.C.G. (NSW)
R11: Carlton @ S.C.G. (NSW)
R13: West Coast @ S.C.G. (NSW)
R16: Geelong @ S.C.G. (NSW)
R18: Gold Coast @ S.C.G. (NSW)
R20: Collingwood @ S.C.G. (NSW)
R23: Hawthorn @ S.C.G. (NSW)
+1 GAMES (x1)
R3: Greater Western Sydney @ S.C.G. (NSW)
-1 GAMES (x1)
R22: Greater Western Sydney @ Sydney Showground (NSW)
-10 GAMES (x10)
R1: West Coast @ Optus Stadium (WA)
R4: Western Bulldogs @ Docklands (VIC)
R6: Geelong @ GMHBA Stadium (Gee)
R8: Hawthorn @ M.C.G. (VIC)
R10: Brisbane Lions @ Gabba (QLD)
R12: St Kilda @ Docklands (VIC)
R15: Richmond @ Docklands (VIC)
R17: North Melbourne @ Docklands (VIC)
R19: Essendon @ Docklands (VIC)
R21: Melbourne @ M.C.G. (VIC)

GREATER WESTERN SYDNEY

The Giants have a balanced fixture that is typical for non-Victorian sides, with ten interstate games away, ten at home, and two local bridge busters.

+10 GAMES (x10)
R1: Western Bulldogs @ UNSW Canberra Oval (ACT)
R4: Fremantle @ UNSW Canberra Oval (ACT)
R6: Brisbane Lions @ Sydney Showground (NSW)
R8: West Coast @ Sydney Showground (NSW)
R10: Essendon @ Sydney Showground (NSW)
R12: Gold Coast @ Sydney Showground (NSW)
R15: Hawthorn @ Sydney Showground (NSW)
R17: Richmond @ Sydney Showground (NSW)
R19: St Kilda @ Sydney Showground (NSW)
R21: Adelaide @ UNSW Canberra Oval (ACT)
+1 GAMES (x1)
R22: Sydney @ Sydney Showground (NSW)
-1 GAMES (x1)
R3: Sydney @ S.C.G. (NSW)
-10 GAMES (x10)
R2: Collingwood @ M.C.G. (VIC)
R5: St Kilda @ Docklands (VIC)
R7: Geelong @ GMHBA Stadium (Gee)
R9: North Melbourne @ Bellerive Oval (TAS)
R11: Adelaide @ Adelaide Oval (SA)
R14: Brisbane Lions @ Gabba (QLD)
R16: West Coast @ Optus Stadium (WA)
R18: Port Adelaide @ Adelaide Oval (SA)
R20: Carlton @ Docklands (VIC)
R23: Melbourne @ M.C.G. (VIC)

ADELAIDE

Adelaide’s fixture is neatly balanced with ten interstate games away, ten at home, and two local showdowns.

+10 GAMES (x10)
R2: Richmond @ Adelaide Oval (SA)
R4: Collingwood @ Adelaide Oval (SA)
R6: Gold Coast @ Adelaide Oval (SA)
R7: Carlton @ Adelaide Oval (SA)
R9: Western Bulldogs @ Adelaide Oval (SA)
R11: Greater Western Sydney @ Adelaide Oval (SA)
R15: West Coast @ Adelaide Oval (SA)
R17: Geelong @ Adelaide Oval (SA)
R19: Melbourne @ Adelaide Oval (SA)
R22: North Melbourne @ Adelaide Oval (SA)
+1 GAMES (x1)
R20: Port Adelaide @ Adelaide Oval (SA)
-1 GAMES (x1)
R8: Port Adelaide @ Adelaide Oval (SA)
-10 GAMES (x10)
R1: Essendon @ Docklands (VIC)
R3: St Kilda @ Docklands (VIC)
R5: Sydney @ S.C.G. (NSW)
R10: Melbourne @ Traeger Park (NT)
R12: Fremantle @ Optus Stadium (WA)
R13: Hawthorn @ M.C.G. (VIC)
R16: Richmond @ M.C.G. (VIC)
R18: Brisbane Lions @ Gabba (QLD)
R21: Greater Western Sydney @ UNSW Canberra Oval (ACT)
R23: Carlton @ Docklands (VIC)

BRISBANE LIONS

Brisbane’s fixture is neatly balanced with 10 interstate games away, 10 at home, and 2 local Q-Clashes.

+10 GAMES (x10)
R2: Melbourne @ Gabba (QLD)
R7: Collingwood @ Gabba (QLD)
R9: Hawthorn @ Gabba (QLD)
R10: Sydney @ Gabba (QLD)
R12: Essendon @ Gabba (QLD)
R14: Greater Western Sydney @ Gabba (QLD)
R16: Carlton @ Gabba (QLD)
R18: Adelaide @ Gabba (QLD)
R20: North Melbourne @ Gabba (QLD)
R23: West Coast @ Gabba (QLD)
+1 GAMES (x1)
R5: Gold Coast @ Gabba (QLD)
-1 GAMES (x1)
R22: Gold Coast @ Carrara (QLD)
-10 GAMES (x10)
R1: St Kilda @ Docklands (VIC)
R3: Port Adelaide @ Adelaide Oval (SA)
R4: Richmond @ M.C.G. (VIC)
R6: Greater Western Sydney @ Sydney Showground (NSW)
R8: Western Bulldogs @ Docklands (VIC)
R11: North Melbourne @ Docklands (VIC)
R15: Fremantle @ Optus Stadium (WA)
R17: Hawthorn @ University of Tasmania Stadium (TAS)
R19: Geelong @ GMHBA Stadium (Gee)
R21: Collingwood @ Docklands (VIC)

WEST COAST

West Coast’s fixture is neatly balanced with 10 interstate games away, 10 at home, and 2 local derbies.

+10 GAMES (x10)
R1: Sydney @ Optus Stadium (WA)
R3: Geelong @ Optus Stadium (WA)
R4: Gold Coast @ Optus Stadium (WA)
R7: Port Adelaide @ Optus Stadium (WA)
R9: Richmond @ Optus Stadium (WA)
R11: St Kilda @ Optus Stadium (WA)
R14: Essendon @ Optus Stadium (WA)
R16: Greater Western Sydney @ Optus Stadium (WA)
R18: Western Bulldogs @ Optus Stadium (WA)
R22: Melbourne @ Optus Stadium (WA)
+1 GAMES (x1)
R20: Fremantle @ Optus Stadium (WA)
-1 GAMES (x1)
R6: Fremantle @ Optus Stadium (WA)
-10 GAMES (x10)
R2: Western Bulldogs @ Docklands (VIC)
R5: Carlton @ M.C.G. (VIC)
R8: Greater Western Sydney @ Sydney Showground (NSW)
R10: Hawthorn @ Docklands (VIC)
R13: Sydney @ S.C.G. (NSW)
R15: Adelaide @ Adelaide Oval (SA)
R17: Collingwood @ M.C.G. (VIC)
R19: North Melbourne @ Bellerive Oval (TAS)
R21: Port Adelaide @ Adelaide Oval (SA)
R23: Brisbane Lions @ Gabba (QLD)

CARLTON

Carlton’s otherwise symmetrical fixture is tarnished by having to travel to Tasmania to play North Melbourne, turning what should be a -1 game into a -5 game.

+10 GAMES (x6)
R2: Gold Coast @ Docklands (VIC)
R5: West Coast @ M.C.G. (VIC)
R13: Fremantle @ Docklands (VIC)
R15: Port Adelaide @ M.C.G. (VIC)
R20: Greater Western Sydney @ Docklands (VIC)
R23: Adelaide @ Docklands (VIC)
+1 GAMES (x5)
R3: Collingwood @ M.C.G. (VIC)
R8: Essendon @ M.C.G. (VIC)
R9: Melbourne @ M.C.G. (VIC)
R18: Hawthorn @ Docklands (VIC)
R22: Western Bulldogs @ Docklands (VIC)
-1 GAMES (x4)
R1: Richmond @ M.C.G. (VIC)
R6: Western Bulldogs @ Docklands (VIC)
R14: Collingwood @ M.C.G. (VIC)
R17: St Kilda @ Docklands (VIC)
-5 GAMES (x1)
R4: North Melbourne @ Bellerive Oval (TAS)
-10 GAMES (x6)
R7: Adelaide @ Adelaide Oval (SA)
R10: Geelong @ GMHBA Stadium (Gee)
R11: Sydney @ S.C.G. (NSW)
R16: Brisbane Lions @ Gabba (QLD)
R19: Gold Coast @ Carrara (QLD)
R21: Fremantle @ Optus Stadium (WA)

MELBOURNE

This analysis may be too optimistic on Melbourne, even though they’re ranked fourth-last. That’s because the Demons host Adelaide and Fremantle in the Northern Territory, and these are classified as +10 games in Melbourne’s favour (hosting an interstate side at an alternative home ground), even though in practice, geography and history suggests it may not be deserved.

+10 GAMES (x5)
R10: Adelaide @ Traeger Park (NT)
R16: Fremantle @ Marrara Oval (NT)
R20: Gold Coast @ M.C.G. (VIC)
R21: Sydney @ M.C.G. (VIC)
R23: Greater Western Sydney @ M.C.G. (VIC)
+5 GAMES (x1)
R1: Geelong @ M.C.G. (VIC)
+1 GAMES (x5)
R3: North Melbourne @ M.C.G. (VIC)
R5: Richmond @ M.C.G. (VIC)
R12: Collingwood @ M.C.G. (VIC)
R15: St Kilda @ M.C.G. (VIC)
R17: Western Bulldogs @ M.C.G. (VIC)
-1 GAMES (x5)
R4: Hawthorn @ M.C.G. (VIC)
R6: Essendon @ Docklands (VIC)
R7: St Kilda @ Docklands (VIC)
R9: Carlton @ M.C.G. (VIC)
R11: Western Bulldogs @ Docklands (VIC)
-10 GAMES (x6)
R2: Brisbane Lions @ Gabba (QLD)
R8: Gold Coast @ Gabba (QLD)
R14: Port Adelaide @ Adelaide Oval (SA)
R18: Geelong @ GMHBA Stadium (Gee)
R19: Adelaide @ Adelaide Oval (SA)
R22: West Coast @ Optus Stadium (WA)

ESSENDON

Essendon host interstate teams only four times but must travel away six times. They get a game against the Cats at the MCG, which helps, but not enough.

+10 GAMES (x4)
R1: Adelaide @ Docklands (VIC)
R4: Port Adelaide @ Docklands (VIC)
R18: Fremantle @ Docklands (VIC)
R19: Sydney @ Docklands (VIC)
+5 GAMES (x1)
R9: Geelong @ M.C.G. (VIC)
+1 GAMES (x6)
R6: Melbourne @ Docklands (VIC)
R7: Hawthorn @ M.C.G. (VIC)
R11: Richmond @ M.C.G. (VIC)
R15: North Melbourne @ Docklands (VIC)
R16: Collingwood @ M.C.G. (VIC)
R21: St Kilda @ Docklands (VIC)
-1 GAMES (x5)
R3: Western Bulldogs @ Docklands (VIC)
R5: Collingwood @ M.C.G. (VIC)
R8: Carlton @ M.C.G. (VIC)
R20: Hawthorn @ M.C.G. (VIC)
R22: Richmond @ M.C.G. (VIC)
-10 GAMES (x6)
R2: Fremantle @ Optus Stadium (WA)
R10: Greater Western Sydney @ Sydney Showground (NSW)
R12: Brisbane Lions @ Gabba (QLD)
R14: West Coast @ Optus Stadium (WA)
R17: Gold Coast @ Carrara (QLD)
R23: Port Adelaide @ Adelaide Oval (SA)

ST KILDA

At least there’s a plausible explanation for Gold Coast’s terrible fixture: the unavailability of their home ground. What’s behind St. Kilda’s shafting, I can’t say. Firstly, the Saints host interstate sides only four times while traveling six times, which is a heavy imbalance in itself. But whereas Essendon are compensated for the same issue with an MCG game against the Cats, there’s no such balm for the Saints, who are bound for Kardinia Park. They also must travel to Tasmania to play Hawthorn, which turns a -1 game into -5.

+10 GAMES (x4)
R1: Brisbane Lions @ Docklands (VIC)
R3: Adelaide @ Docklands (VIC)
R5: Greater Western Sydney @ Docklands (VIC)
R12: Sydney @ Docklands (VIC)
+1 GAMES (x7)
R7: Melbourne @ Docklands (VIC)
R9: Collingwood @ Docklands (VIC)
R17: Carlton @ Docklands (VIC)
R18: Richmond @ Docklands (VIC)
R20: Western Bulldogs @ Docklands (VIC)
R22: Hawthorn @ Docklands (VIC)
R23: North Melbourne @ Docklands (VIC)
-1 GAMES (x4)
R2: North Melbourne @ Docklands (VIC)
R10: Richmond @ M.C.G. (VIC)
R15: Melbourne @ M.C.G. (VIC)
R21: Essendon @ Docklands (VIC)
-5 GAMES (x1)
R6: Hawthorn @ University of Tasmania Stadium (TAS)
-10 GAMES (x6)
R4: Geelong @ GMHBA Stadium (Gee)
R8: Fremantle @ Optus Stadium (WA)
R11: West Coast @ Optus Stadium (WA)
R13: Gold Coast @ Carrara (QLD)
R16: Port Adelaide @ Adelaide Oval (SA)
R19: Greater Western Sydney @ Sydney Showground (NSW)

GOLD COAST

The Suns immediately drop 20 points by playing a home game against Fremantle in Perth, which turns what should be a +10 game into -10. Then there’s a home game against Port Adelaide in China, knocking down a +10 game to +1 (nominal home team in neutral venue). It leaves them with 11 games where interstate advantage will work against them and only eight when it will be in their favour.

+10 GAMES (x8)
R1: North Melbourne @ Cazaly’s Stadium (QLD)
R8: Melbourne @ Gabba (QLD)
R11: Geelong @ Carrara (QLD)
R13: St Kilda @ Carrara (QLD)
R15: Collingwood @ Carrara (QLD)
R17: Essendon @ Carrara (QLD)
R19: Carlton @ Carrara (QLD)
R21: Richmond @ Carrara (QLD)
+1 GAMES (x2)
R9: Port Adelaide @ Adelaide Arena at Jiangwan Stadium (CHI)
R22: Brisbane Lions @ Carrara (QLD)
-1 GAMES (x1)
R5: Brisbane Lions @ Gabba (QLD)
-10 GAMES (x11)
R2: Carlton @ Docklands (VIC)
R3: Fremantle @ Optus Stadium (WA)
R4: West Coast @ Optus Stadium (WA)
R6: Adelaide @ Adelaide Oval (SA)
R7: Western Bulldogs @ Mars Stadium (VIC)
R12: Greater Western Sydney @ Sydney Showground (NSW)
R14: Hawthorn @ University of Tasmania Stadium (TAS)
R16: North Melbourne @ Docklands (VIC)
R18: Sydney @ S.C.G. (NSW)
R20: Melbourne @ M.C.G. (VIC)
R23: Geelong @ GMHBA Stadium (Gee)

https://www.bigfooty.com/forum/threads/fixture-analysis-2018-home-ground-advantage.1187491/

It’s 2018!

And Squiggle is ready to track every part of it.

Over on Live Squiggle, we’re getting bullish on Port Adelaide and expecting the Crows to remain a force.

The Cats and Giants still have a bit to prove, though, after accumulating quite a few close wins in 2017, which is always suspicious. So while those two teams are contenders, they’re a tier below the top 4 prospects of Adelaide, Port, Richmond, and Sydney.

The Bombers are a good chance to make finals for the second year running, and the Saints lead a pack of clubs vying for a place likely to be vacated by West Coast.

In 2018, Squiggle is powered by a new algorithm! The main differences to last year’s model are:

  • Squiggle 2.0 is much more sensitive in the early rounds, so surprising results will cause a lot of chart movement. This better captures the substantial form change that can occur over an off-season.
  • Squiggle 2.0 considers goalkicking accuracy: It slightly discounts scores that were the result of unusually high accuracy (i.e. kicking many more goals than behinds), and is forgiving of scores that were the result of unusually low accuracy, as this tends to be non-reproducible.

We’ll see if this is enough to move up the Computer Model Leaderboard! Of course, it would be hard not to. 2017 was not a kind year.

I hope to have all the usual gang of Squiggle friends on board again, bringing you the best of online AFL analysis from around the web, and perhaps a couple of new additions.

Thank you for following Squiggle 2018!

Squiggle on Grand Final 2017

Richmond Tigers
Premiers 2017

Well holy shit! In animated form:

In Flagpole form:

Obviously I’m posting the above just for the enjoyment of Richmond fans, not because it offers any kind of analytical insight. That much is clear, because if there’s one thing Squiggle has been consistent on this year, it’s that THE TIGERS WILL NOT WIN THE PREMIERSHIP. It didn’t rate them as a team until late, and even then was confident that somewhere, sometime, the defensive gameplan would unravel as a more balanced side got hold of them and shook until all their mediocre players fell out.

Instead, for reasons that leave me equal parts baffled and tumescent, Adelaide turned up on Grand Final Day and played listless football. At no point did it look like an Adelaide game; instead, it always resembled a Richmond game: close and scrappy, with Tigers outworking and outrunning their opponents, taking risks, swarming, and halving and winning contests one by one until the weight of numbers was too great to resist.

In this way, it was the same story as the two previous Richmond finals – moreso, if anything, than the preliminary final, where GWS at least occasionally managed to look like a team not playing Richmond. Where Squiggle expected the Tigers inevitably to break down, they barely showed a crack.

Why this happened requires a closer look at game style than I can provide. But we can examine how unusual it is, and how it fits (or doesn’t) with other modern premierships.

Richmond’s triumph replaces the 20-year-old 1997 Adelaide premiership on the chart, leaving something of a two-island effect, with four defence-oriented flag teams set a short distance away from 16 balanced or attacking ones. On its face, that still looks like evidence that low-scoring teams do worse, especially if you consider the number of wrecks of premiership campaigns located here, most of which belong to Sydney, Fremantle and St. Kilda. But it’s very noticeable that it now hosts the two most recent flags. In fact, by the time next season rolls around, you will have to go back seven years to find a premier that wasn’t either defensively-oriented or Hawthorn.

So is it still better to be attacking? Plenty of evidence remains for the benefits of attacking football, but it stops rather abruptly at the end of 2015. In 2016, the four most defensive teams made prelims, while Adelaide, a high-rated attacking team, fell out unexpectedly in the semi-finals. 2017 has been more ambiguous, with another finals failures from defensive specialists Sydney (and, to a lesser extent, Port Adelaide), but a dominant finals campaign from the Tigers. Whether this means the game has evolved, it’s a temporary aberration, or squiggle has no freaking idea what it’s talking about, I leave to you.

In terms of raw dominance, the 2017 Tigers are rated tenth of those 20 flags, so pretty much bang in the middle, but 2nd for defence and 18th for attack.

The Tigers didn’t come from as far back ahead of finals as the Bulldogs did last year – no-one has – but they did move a long way by thrashing all three opponents. They also moved a long way over the course of the season, after a lacklustre 2016 that ended with an 88-point loss to the Giants and a 113-point belting at the hands of the Swans. Some travelled further, but no modern premier has started the year as far back as Richmond did in 2017.

On balance, the Bulldogs 2016 premiership remains the greater anomaly, given how poor they were leading into finals, the need to win 4 straight games, two of which were interstate, and the strength of their opposition, which was greater in 2016 than offered by the top four this year. But the Tigers are up there, particularly (from squiggle’s point of view) since they found success with a low-scoring game style that has a terrible historical strike rate.

Richmond had a generous draw in 2017, with only one double against a top-8 opponent (GWS) and three doubles against the bottom 5 (Carlton, Brisbane, Fremantle). It was also a good year to be thereabouts, with a very even competition and no dominant team; probably the least competitive top end field since 2009. But they were also unlucky not to have another close game or two fall their way, deserved to finish top 4, and were emphatic in dismantling each opponent once they got there.

On a personal note, thank you for following Squiggle 2017, and the earlier ones, if you’ve been on board for that. It’s been an amazing ride. But I think this is a good place to leave it, with the team I love obliterating my algorithm and demonstrating how much greater the game is than all the bullshit I do here. So I will stick around BigFooty but not start a squiggle thread next year. In the words of a great man, I am going to spend some time on my novel.

And again, holy shit. I remember complaining about how bad the Tigers were with a guy on my bus, and him saying don’t worry, we’d come good in a couple years. That was around 1986. We were on our way to school. I’ve followed this team through the 29-year period where we missed the finals 27 times. People don’t appreciate that; the numbers are too big to really comprehend what it’s like to be bad year after year and have that go on almost without break for three decades. Until this year, I’d never seen Richmond win a final in person – I have seen us get smashed from the opening bounce twice – and was too young to remember the last time we made a Grand Final. But now. Holy fucking shit.

I was expecting to be able to report here my experience on which is really worse: being bad forever or losing a Grand Final. All I can say is I still suspect it’s the first one.

I like football because it’s so divorced from reality, it doesn’t matter what else is going on in your life, everyone’s on common ground. It doesn’t matter who you are. You can connect to people and everything about the two of you is irrelevant except what you think of the teams, or how badly the AFL are managing the rules. It strips us all down to something simple and clean. That’s a great thing.

May your off-season be brief, your trades fruitful, and your spuds delisted.

Much love,

Max.