Review round up

And so we come to the yearly comparison piece whereby this year’s performances, numbers wise, are stacked up against preceding years.

In previous versions of weightings 2010 data had been used, in conjunction with 2012 & 2013, so as to create more volume (and as the reasoning goes more accuracy). From here on all 2010 data will be omitted. There is no great reason for this, as the averages more or less stack up, but it just feels more complete to have continuous year’s returns rather than an outlier with a year’s hiatus in between. At this juncture, after taking a year out in 2011, there is no guarantee that the 2010 methodology was the same as is used now. 2010 was the first year of doing the tracking – I’m pretty sure issues were being ironed out throughout that year so 2012 data onwards just feels more robust.

With that said here are the numbers

Year Attacks Shots Shot Rate Scores Success Rate
2012 35.28 27.02 76.6% 13.96 51.7%
2013 36.32 28.26 77.8% 14.26 50.5%
2014 39.83 30.88 77.5% 15.85 51.3%
averages
2012/2013 35.8 27.6 77.2% 14.1 51.0
all 37.0 28.7 77.7% 14.7 51.2%

Essentially Shot & Success Rates for 2014 stayed very close to 2012 & 2013 levels – once teams had the ball inside the opposition’s 45 the ultimate overall ratio of shots & scores from those possessions stayed the same.

The difference comes in the volume of attacks. There was a 9.7% increase per team in attacks on the 2013 returns. This is quite significant. Of course if the volume of shots and accuracy of shooting is constant on an increased volume of attacks you will get more scores; and that’s what happened with an increase of 1.6 scores per team per game.

So why have the volume of attacks increased so dramatically? Many put the increase squarely at the feet of the black card. It has undoubtedly had an affect but I’m a firm believer that this is a copycat game and Dublin’s successful swashbuckling style throughout 2013 & 2014 will also have had an impact on how team’s approach the game. Although smaller there was an increase of 2.9% without the black card in 2013.

If it was all the black card I would expect that what happened inside the 45 would be as affected by what happened outside. Players would have more time/space to shoot – less people pulling at their arm/jersey. The numbers don’t bear this out however. Yes the black card allowed for less attacks to be stopped by illegal defending up front but there was no boon to the shooters.

Deadballs

Another area where the black card has been given credit is the reduction in the volume of frees. Yes there was a decrease in the volume of deadballs per game in 2014 but this decrease was only back to 2012 levels. Is this decrease then the black card affect or simple variance?

I am not for one moment saying the black card is a bad idea. Or that it has had no effect. I would argue that there are many variables that lead to a shift in trends of which the black card is one. And trying to quantify the value of that one variable is incredibly difficult.

Year Shots Scores Success Rate
2012 6.94 4.64 66.9%
2013 7.78 5.18 66.6%
2014 6.75 4.94 73.1%
averages
2012/2013 7.36 4.91 66.7%
all 7.16 4.92 68.7%

Some of the more seasoned observers will note the increase in the deadball Score Rate. One of the central planks of the data to date is that your deadball strikers will return a 67% Success Rate. Even 2010 returned a 66.3% Success Rate. This has jumped to 73% this year – for more detail on why this is please see here

So what of shooting from play?

Year Shots Scores Success Rate
2012 20.08 9.30 46.3%
2013 20.48 9.08 44.3%
2014 23.79 10.77 45.3%
averages
2012/2013 20.28 9.19 45.3%
all 21.42 9.70 45.3%

Essentially there was no change in the accuracy; it came in bang on the 2012/13 average.

I did a quick comparison of shots for points versus shots for goal. Some of the noteworthy outcomes
• The Success Rate for point taking in 2014 was more or less the same as 2013 – 44.8% versus 44.7%.
• The overall increase in Success Rate from play was almost entirely due to goal shots being converted at a higher level; 48.6% in 2014 versus 41.9% in 2013
• One of the more volatile ratios is point attempts per goal shot; 2012 = 7.58, 2013 = 6.53 & 2014 = 7.13. Generally speaking the increase in shots from play was more weighted towards goal shots but not in any dramatic sense

Weighting

Some of the deficiencies in the weighting were outlined earlier in the year (here) – especially when it came to less frequent events like penalties, attempts from sideline balls and goal shots that go for a point.

Due to a lack of data, both in terms of not capturing data in 2010 and events occurring infrequently, some subjective judgement had been applied to the weighting in these cases. Although the rationale behind the judgement calls made sense (to me at least!) it is something I’ve always wanted to remove. With three consecutive years’ worth of data, where the same methodology has been consistently applied, that is now possible.

That is not to say the new weighting is complete – there are still some very small volumes on penalties, sideline balls etc. but it is better to just take the numbers and deal with any issues that arise thereafter rather than try to overlay a subjective value.

On top of stripping out any subjective overlay the 2010 data has been removed. The below tables show the differences between the weighting employed in 2014 and what will be applied going forward

From play

Sector New Weighting Old Weighting Difference
1 0.667 0.707 -0.040
2 0.605 0.623 -0.018
3 0.750 0.698 0.052
4 0.628 0.641 -0.013
5 0.501 0.501 -0.001
6 0.653 0.641 0.012
7 0.579 0.575 0.004
8-point attempt 0.288 0.292 -0.004
8-goal attempt (goal) 0.662 0.593 0.069
8-goal attempt (point) 0.288 0.593 -0.305
9 0.538 0.683 -0.045

From deadball

Sector New Weighting Old Weighting Difference
1 0.600 0.643 -0.043
2 0.526 0.519 0.008
3 0.731 0.629 0.102
4 0.379 0.453 -0.074
4 – 45s 0.524 0.565 -0.041
5 0.163 0.160 0.004
5- 45s 0.506 0.500 0.006
6 0.397 0.428 -0.031
6 – 45s 0.611 0.565 0.0.46
7 0.180 0.232 -0.051
8 – frees 0.064 0.087 -0.023
8 – penalties 0.182 0.593 -0.411
9 0.211 0.227 -0.016
Sidelines 0.688

The weightings have not moved all that much with the main differences coming around goal attempts.

Previously if a player went for goal and got a point he got the same weighting as if he’d scored the goal. This was slightly absurd so now in that instance a player will get the same weighting as if he’d gone for a point. Probably not ideal (he should get some extra bump for going for goal) but I think it’s better (or less bad!) this way. Similarly a player got the same weighting for scoring a goal from a penalty as from open play. Given that penalties are converted at 82% this over sold a converted penalty. The weighting now reflects this conversion rate.

In the coming days I will overlay this new weighting on all games from 2012 onwards and see what shakes loose.

Advertisements

7 Responses to “Review round up”

  1. Brian Donohoe Says:

    awesome analysis guys thanks

  2. Niall Says:

    Really interesting stuff! Can you explain as to what are the characteristics of an “attack”?

  3. Top performances over the last 3 years | dontfoul Says:

    […] Shining a light onto GAA stats « Review round up […]

  4. Kerry V Kildare 2015 All Ireland QF | dontfoul Says:

    […] scored 5-01. The data doesn’t include 2015 games but from 2012 to 2014 one third of goal attempts are converted … you allow 8 goal shots a game, with the opposition converting 75% and you’re […]

  5. 2015 Season Review – Part I | dontfoul Says:

    […] – it was more the black card being acclaimed for leading to open play) however here on the blog judgement was reserved. The black card was part of the reason but it could as easily have been a one year outlier as much […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: