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

How to win in Super League

Listeners to the show will know that we do what we can with the free stats available on the Super League website. One thing that I've been looking at in the off season so far is which of these stats seems to be most important to winning games in Super League.

In a simple breakdown, I've looked at every winning result over the time that the show has been running (so, from 2014-2017). I've counted up when the winning team had the most a particular stat count, when the count was equal between the sides, and when the winning team had less in a stat count than their opponents - then turned these into percentages of the games with a winning result (i.e. not a draw).

The below two charts show the results of the simple process.
The first chart is the basic stats: Tries (T), Tackles (TK), Marker Tackles (MT), Missed Tackles (MI), Tackle Busts (TB), Attacking Kicks (AT), Carries (C), Metres (M), Average Gain per carry (AG), Clean Breaks (CB), Runs From Dummy Half (DR), Errors (E), Goals (G), Missed Goals (MG), Offloads (OF) and Penalties Conceded (P).
The second chart has four stats adapted from those basic ones: Tackle Success Rate (TK%), Goal Success Rate (G%), Positive Impact Plays (TB+CB+OF) and Negative Impact Plays (MI+E+P).

Chart 1

Most of the headline results are fairly obvious - the team with the most tries and goals wins almost all the time. You'd also expect the team making the most metres, the most tackle busts (so also the fewer missed tackles) and most clean breaks to win much more often than lose.

• 86% of games are won by the team who scores the most tries - only 12 of the 684 games in the period were lost by the team who scored the most tries.
• 85% of games are won by the team who kicks the most goals (although 52% are also won by the team who misses the most goals!).
• 79% of games are won by the team who makes the most metres, and 71% by the team who makes those metres at the best average gain.
• 71% of games are won by the team who makes the most tackle busts (and, as a complementary number, 71% are won by the team with the fewer missed tackles).
• 70% of games are won by the team who makes the most clean breaks.

It's also clear that using your energy with the ball rather than without the ball is fairly important for success - the team with the most carries and making fewest tackles has a much better win rate than the other way round.

• The team with the most carries wins 69% of the time.
• The team with the fewest tackles wins 71% of the time, the 5th highest indicator of all these stats.

What is interesting is that errors, and in particular, offloads and penalties aren't as decisive as we might think.

• The team who makes fewer errors has won 61% of the time, so it's still an important factor in winning, but it's only the 11th most decisive stat of the 16 shown in Chart 1.
• The team who makes the most successful offloads only wins half the time.
• Similarly, when a team concedes fewer penalties they only win half the time.

 Chart 2

These results are a little more interesting still.

This shows having an overall better tackle success rate is very useful, but not as important as not having to make as many tackles in total.

It also shows that kicking at a better success rate than your opponent isn't that important, as long as you're taking more kicks at goal like Chart 1 shows.

Finally, it shows that whilst positive and negative plays are both important, it's more important that you don't make the bad plays, as making more of those has a greater impact on whether you win or not. Now, from Chart 1 we know that it's probably the missed tackles part of this that will hurt your chances most, so this shouldn't mean teams can't take risks in attack - it just means any mistakes in attack have to be backed up by a strong and secure defensive line.

Whilst this isn't the most sophisticated analysis you'll ever see, it is still somewhat informative. In games between evenly matched sides, take a look at who leads the way in the stats that count most when picking a winner.

Thanks for reading. Look out for our special podcast episodes during the off season. For iTunes users, head HERE. For the rest of you, you'll find us HERE.

Mark
SLP