Taking the Two - the Super League trend for penalty goals

Last week friend of SLP Mark posed a question that he just knew I couldn't resist digging deeper on. He had a feeling that sides were taking more penalty goals this year than in the recent past.

We took up the topic in Episode 174 of the show. I threw out some hastily worked together numbers, Tim threw up some follow-up questions, the outcome of it all has become this blog post!

Are teams taking the two more?

Yes.

Both in the early stages of 2018, and as a growing trend since the Super 8s era started in 2015, teams seem to be taking the two more.

Using the fairly crude and straightforward, but pretty much reliable, method of goal attempts minus tries, you get the amount of goal attempts that weren't conversions, which will be the penalty goals.

You can see that both the penalty goals per game and the percentage of goals that are made up by penalty goals is higher year-on-year.

I've also looked at all the teams in Super League and, generally speaking, the same trend is seen at each club. All sides but Leeds, Wakefield and Wigan - three of the top four sides at time of writing - have their highest percentage of penalty goals over the last four seasons in 2018. The six highest percentages in the whole table are all from this year.

So, why is this happening? Well Tim put forward a number of questions during the show that might shed some light on why.

Are kickers getting better, making teams more likely to take the two?
No, not really.

Goal kicking success across the league has been pretty steady between 2015 and now, between 74% and 75%. The only time it dips lower in the period was the opening period to 2017, at 73%, but that was the second highest time for penalty goals being taken.

Looking at individual teams, it offers a few examples to support Tim's idea that teams will take the two more if they have a better goal kicker. However, there's as many examples to contradict it as there are to support it. There's certainly no clear causal relationship there, just a very small positive relationship. Better kickers may encourage you to take the two more, but it's not why we've seen more penalties taken.

Are we getting more penalties, so kicking more penalty goals?
Maybe.

There does appear to be a reasonable, but not hugely strong, positive relationship between the amount of penalties and the amount of penalty goals. It hard to draw a stronger conclusion than that because we don't know where on the field penalties are given for each season looked at, and we don't know how close the games were at the time penalty goals were taken. It could just be that more penalties this year are in kick-able range, or the ones in kick-able range have been given more often when the scoreboard says to take the two.

Although, the highest penalties per game figure in the top table above was early in 2016. That was the third lowest penalty goals taken figure in the table. So, we can't say conclusively that more penalties is the main cause of why we're seeing more penalty goals.

Is it the weather?
Very hard to say, but I think unlikely.

The bad weather to start the 2018 season has been fairly unprecedented. So maybe it has had an impact that would be hard to compare with other years in the Summer era. Regardless, it will still have been at it's coldest in the opening rounds of 2015 and 2016, when teams were less likely to take the two than later in those years.

Is it closer defences?
This was Tim's first question, and it's the most likely explanation.

It's clear from the top table above that as penalty goals per game are going up, tries per game are going down. There's a fairly strong negative relationship between the two figures.

And I'd like to think that's because defences are getting better, rather than it being attacks are getting worse, at least that's a more positive way to spin it!

Obviously, if you and your opponents are less likely to score four-pointers, the two points from a penalty goal are in theory more valuable in helping you win the game than if defences are leaky and tries are easy to score.

As always, thanks for reading and I hope you've found this interesting. If you've enjoyed the read, don't forget to get yourself involved with the weekly podcast for some lively and hopefully well informed Rugby League chat.

Mark
SLP