Goal Kicking Probabilities | PUNT ROAD END | Richmond Tigers Forum
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Goal Kicking Probabilities

Coburgtiger

Tiger Legend
May 7, 2012
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Over the last couple of years, I've constantly bemoaned our frustrating delivery to difficult targets inside 50, wondering why the players, and the coach, seem to continually invest in this plan.

My understanding is that Dimma likes the 'percentage option'. He's interested in probabilities, to the extent that he wants to manoeuvre the ball in such a way, that we are a low percentage chance of being scored against. Even when in attack. I believe that he backs this logic up with the idea that a short kick from inside fifty, even on an angle, is a better chance than a bomb from outside fifty.

That's the idea that I want the coaching staff to really think about. Are you a better chance of scoring from a shot inside fifty than out? Probably. Are you a better chance to score by taking that option? Probably not. At least not by what I understand of probability.

Let's say Griff or Deledio mark the ball 55 out. For whatever reason, they seem to be instructed to look inside for a forward option in a better position.

So, in terms of probability, there's a couple of situations here.
1. Griff takes the shot.
2. Griff passes to someone (maybe Cotchin), who then takes the shot.

My issue, is that the second option requires 2 successful disposals. The first only requires one.

Let's say Griff is a 50% chance of nailing the goal from 55. Let's say Cotchin is a 60% chance of kicking the goal, because he's in a slightly better position. Football logic says, give it to the guy with the higher percentage chance of kicking the goal.
But I would suggest that this leads to a lower overall chance of getting a goal. Let's say the Cotchin gets on the move, and Griff tries to hit him on the chest. Let's say he's a 75% chance of completing this pass.

In situation 1, Griff is a 50% chance of scoring. In situation 2 he's a 75% chance of hitting his Cotchin, who is then a 60% chance of kicking a goal - leading to an overall possibility for scoring of 45%.

Yes, Griff's pass to the Cotchin is a higher percentage pass than the shot. Yes, Cotchin is a higher percentage chance of scoring from that position. But overall, we are less likely to score.


Now these percentages are made up and a bit random. But the logic is, trying to hit up multiple options, even if they're good ones, is often going to lead to a lower chance of scoring.

Obviously, if it was Morris lining up from 55, who would be a 0% chance of scoring, then, you need to pass it off. But in the situation where a player is 50/50 to snag one from distance they should be having a ping. It's extremely unlikely they're going to increase our chance of scoring by trying to hit up a target. Obviously, the more congested the forward line is, the less likely that initial pass is. And our forward line is always congested.

So no, I don't think this is pointing out anything of massive importance about our gameplan, but as Hardwick is such a stats man, I'd like to see the directive given to every player that if you're within range HAVE A CRACK.

It's why I didn't really mind Vickery marking that ball and immediately taking responsibility for making the kick. I reckon he'll nail that shot 9 times out of ten, and probably be able to hit Grigg running into goal about 9 times out of ten. Grigg is probably going to then kick that goal 98 times out of a hundred, but put the two together, and it's still less likely than Vickery just having the shot.
 
"It's why I didn't really mind Vickery marking that ball and immediately taking responsibility for making the kick. I reckon he'll nail that shot 9 times out of ten, and probably be able to hit Grigg running into goal about 9 times out of ten. Grigg is probably going to then kick that goal 98 times out of a hundred, but put the two together, and it's still less likely than Vickery just having the shot."

No-one kicks at 90% or 98% , AFL average is 50% IIRC.

But i get the gist of what youre saying.
 
Unless we want to have the lowest conversion rate of everyone in the AFL, we shouldn't have everyone having a crack from any position within 60 metres of goal IMO.

That argument is based on assumed statistics while the coaching staff have real statistics. It would require a major elementary mistake in probability by multiple coaches to fail to factor in the probability of getting the ball from the 'goal assist player' to the 'scoring attempt player'. But you're right to say it's inefficient.

Improve the efficiency of manoeuvring the ball into our F50 and our goal conversion could rise from 55% to 65% and we'd win more games. Easier said than done though. Slingshot footy seems to help as you move the ball fast enough to find enough free players in the F50.
 
Interesting thought process but difficult to put percentages on kicking in certain or even most situations - too many variables.

IMO, Griffiths long kicking is a touch exaggerated, if not over rated.
 
jb03 said:
Interesting thought process but difficult to put percentages on kicking in certain or even most situations - too many variables.

IMO, Griffiths long kicking is a touch exaggerated, if not over rated.

I reckon the mechanics of his kicking action make it difficult to kick accurately.

It's such a long follow through. Legs are too long.
 
jb03 said:
Interesting thought process but difficult to put percentages on kicking in certain or even most situations - too many variables.

IMO, Griffiths long kicking is a touch exaggerated, if not over rated.
Why, TV does it for each player on set shots?
 
Bill James said:
Why, TV does it for each player on set shots?

Those stats are unclear as to what conditions they are given (and are possibly not accurate). For example, are the stats skewed by playing many games indoors at Etihad then next game you are kicking from 50 metres with a wet ball in windy conditions.
 
Coburgtiger said:
Over the last couple of years, I've constantly bemoaned our frustrating delivery to difficult targets inside 50, wondering why the players, and the coach, seem to continually invest in this plan.
...

A very 'Barassi' way of looking at the game. Reckon he'd applaud.
 
Traditionally Hardwick's forward entry plan was kick it long deep into the pocket. If we don't mark it engineer a boundary throw in or a ball up. If you do mark it take your kick and from that angle the odds are about 33%.

So the end result of this style of negative forward 50 entry would result in ( if you have 60 forward entries for the day and have scoring shots from 50% of those entries) a score od 10 goals 20

On these occasions Hardwick has bemoaned the kicking accuracy that has cost the match but never once has Hardwick admitted that his game plan was at fault.

On the weekend the team accidently played a different style going into the forward line kicking a higher % to the centre corridor and the end result we kick 16 goals 9 points.( it also helped that we brought the ball in fast)

The frustrating issue is that Hardwick then says it is not the way we want to play going forward.
 
Carter said:
I reckon the mechanics of his kicking action make it difficult to kick accurately.

It's such a long follow through. Legs are too long.
So what effect does follow through have? Only real thing that matters is position of foot relative to ball n power at point of contact. You can have all the follow through you want after the ball has made contact n gone, it's just stylin. Looks fancy but does nothing.

Pretty sure Ty's legs would be a similar length to Griff's n so would Beanie's.
 
TigerMasochist said:
So what effect does follow through have? Only real thing that matters is position of foot relative to ball n power at point of contact. You can have all the follow through you want after the ball has made contact n gone, it's just stylin. Looks fancy but does nothing.

Pretty sure Ty's legs would be a similar length to Griff's n so would Beanie's.

follow through is everything.

if you have a follow through it means you're the pushing through the ball more.

some of the best AFL / VFL set shots in the past have been stabbers. you can get better accuracy in the 0-40m range with a stab.

griff has the same wind up and follow through whether he's 60m out or 10m out. its's a long range action every time.

its technically correct but at short range he doesn't caress the ball in between the sticks, he fires a long range blast that doesn't deviate. if it ain't on line it isn't gonna drift or spin laterally.

watch jack kick the ball. not great at 50+ metres because his follow through is much less. this gives him more control. he can give the ball a slight hook or a fade. his accuracy at 30-50m from any angle is elite.
 
KnightersRevenge said:
Ask a golfer,
So club head hits ball at 100 plus kph impact lasts for all of a millisecond, but it's all about the stylish balanced follow through after the ball is already twenty meters off the club face. Yep gotcha.
 
It's a bit more complicated than that TM, the foot as it make contact with the ball remains in contact for a fraction of a second in this time the foot may have travelled 15 cm. To ensure that the required amount of force is applied the foot speed is many times at near maximum.

Imagine the inertia of the leg weighing about 15 kg traveling at maximum speed, after the ball leaves the foot the momentum still carries the leg forward on the follow through. The foot can't be stopped dead the moment after the ball has left the foot unless you want risk an injury.
 
yandb said:
On the weekend the team accidently played a different style going into the forward line kicking a higher % to the centre corridor and the end result we kick 16 goals 9 points.( it also helped that we brought the ball in fast)

The frustrating issue is that Hardwick then says it is not the way we want to play going forward.

That sounds highly subjective - I assume you have evidence for this or do you make it up so it neatly supports your argument to assume it was in fact an accident.
 
YT you are correct (just going on memory) but if you watched on the couch, Hardwick does imply that that was not how he had planned the team to play. If that is the case then the game plan the team played on Sunday was an accident.

I am going on memory here (I deleted the recording of on the couch on Wed.) Even if he didn't use the exact words he says that' This is not the way we want to play going forward'. YT if you have the recording you can confirm the exact words that Hardwick used.
 
yandb said:
YT you are correct (just going on memory) but if you watched on the couch, Hardwick does imply that that was not how he had planned the team to play. If that is the case then the game plan the team played on Sunday was an accident.

I am going on memory here (I deleted the recording of on the couch on Wed.) Even if he didn't use the exact words he says that' This is not the way we want to play going forward'. YT if you have the recording you can confirm the exact words that Hardwick used.

Your memory is correct, but there's also the possibility they intentionally used a different gameplan to what they'd prefer to use in order to counteract Collingwood's game. I don't think you play slingshot footy by accident, you need to throw players behind the ball, and the coach wouldn't let players play out of position for 120 minutes.

Hopefully he's 'forced' to use that style more often!