Tracking how well NRL teams win – and lose

Looking at the Round 16 NRL draw, I couldn’t help but think the Tigers were the weekly special, certain to rack up a 13+ victory over the Raiders on Saturday night.

They need to, right? They are well behind where they need to be in their Points Differential (-33). So, even though they have equal competition points to the Eels and Storm, they are still behind them by virtue of that inferior differential. Not that those two teams are doing well in this respect either, I should add. It could literally mean the difference between making, or missing, the Top 8 for the Tigers, and needs urgent attention.

The scene is set for them to post a big win against a club in turmoil, and who are playing the sort of uninspired football that validates their 3rd-last position. And if they can’t do it against the Raiders, one wonders who they can do it to.

But how likely is it? Of their seven wins this year, only two have been 13+ (a 30-point margin over the Titans in Round 2 and a 16-point win against Manly in Round 5 – both quite some time ago). The rest have averaged 5.8 points, or a median of just 3pts.

(I like the median with smaller data sets because it clips off the outliers and gives us a central tendency).

Below is the median win margin of all teams over the 2014 so far:Median Win

Hmm, maybe I’d better look deeper into this before splashing out on a 13+ ticket for this match – if I even end up going there at all, as now seems unlikely! With a median of 9pts, the Tigers and 13+ results don’t seem to fall into the expected category.

As for the Raiders, their average losing margin this year is 16.8pts, with a median of 13pts, but the last five matches are somewhat better (loss average 13pts and median 11pts – with a win thrown in). So far, the Tigers 13+ isn’t quite stacking up as I’d hoped, but all is not lost yet.

Over this period, the Tigers have had three clear losses to superior teams, but only beat the Sharks by 2pts and the Knights by 3pts. Yes, the bottom two teams.

Let’s add in for good measure the record at the poorly supported Campbelltown Stadium – a 12pt win against the Cowboys, who can’t even get interested south of the border, and a narrow loss to the Broncos.

Uggh … Tigers 13+ just doesn’t stack up for risk/reward. Even if the Tigers win by 30pts tonight, I won’t be upset about not having put on the 13+ bet. It leaves a little more to chance than I would like, and I’m not that lucky! And you’re not getting paid to take the risk (13+ at 2’s? Nah ah).

Maybe we can salvage something though. The two matches played at Campbelltown were relatively low-scoring – 20pts and 30pts respectively. With the Over/Under line at around 42-44 (depending on agency), perhaps there’s an angle. The median total points of all Tigers matches this year is 42pts, and 46pts for the Raiders. So, the Over/Under looks right from an historical numbers sense, but still a little high given form and venue.

Ranking the Win & Loss Margins

Parramatta’s collection of losses (the worst in the NRL) initially motivated me to look at the margins by which teams typically win and lose, but hadn’t done anything until prompted by this Tigers match and a desire to see if having a lash was worth it.

The Eels’ loss against the Tigers in Round 7 was bad enough considering their dominance that day, but following it up with a thumping at the hands of the Cowboys was a fortnight that (I thought at the time) set their Finals hopes back and may come back to haunt them. Then again, subsequent losses have been equally as bad! How bad?

Check out the following chart, highlighting just how poorly the Eels have performed when losing matches. It’s very unlike what you’d expect from a team clinging to 8th spot.Median Loss

Even if the Eels have the attack worthy of finalists, they don’t have the defence at this point. So, while I’d personally like to see some of their champ(Hayne) best in September, I’m not betting on it.

You can lump the Tigers into that category as well. In both cases, it doesn’t auger well for Finals football against the current Top 6, who demonstrate far greater resolve when behind on the scoreboard. Cultivating that sort of attitude becomes a habit, and teams can’t draw upon it when needed if they don’t have it.

The surprise packet in the chart above is clearly the enigmatic Cowboys. A median loss of just 4.5pts (and an average of just over 8pts)? Really? Well, onsider that five of their losses have been within a 1-5pt range. Throw in losses of 8pts and 12pts, and the only big (Origin-affected) loss was the 30pt drubbing by the Raiders. As far as loss records go, that’s pretty impressive. And it’s made me rethink their match against the Rabbitohs too!


How You Doin? Updating Your Team’s Draw Strength

An earlier (pre season) blog on the subject of each team’s draw strength sought to highlight who had the best chance of getting off to a good start in season 2014.

Using last year’s Minor Premiership results and making some allowance for Home and Away matches, it looked like this:Draw Strength 1st 8 rounds adj

Now that we’re one sixth of the way through the 2014 draw, how is it looking? More importantly, given the surprises that have marked the early rounds and the odd look of the NRL ladder, how does the next group of games look?

The Cowboys are the notable failure so far on this metric. They haven’t even left Queensland, and won’t until Round 6, yet have won just the solitary game. They’re off to a slower start than the 40 year old virgin, and that’s with a fantastic draw. I likened their Auckland 9s success to teh US Masters par 3 tournament, but didn’t think they’d fall out of contention this quickly. The only positive thing to say is that there is still 20 games to go … there’s time to resurrect this abomination of a start.

Of course, based on any metric at all, favourable draw or not, the Bunnies have stunk up the joint, and are beginning to resemble the North Sydney Bears and the 2007 Dragons all in one. The former couldn’t win finals matches and were boring with boring jerseys (yes, I choose my wine based on the label), and the latter began to drop off the face of the earth after failing in two consecutive Preliminary Finals. What you will see below won’t give their fans any cheer whatsoever!

The Dragons and Bulldogs have managed to overcome what appeared to be a fairly tough draw for the first two months of the season, though it must be said, of that eight week span, the Dragons’ first half was monumentally easier than what they are about to face in the next four weeks. Put it this way, if they are on top of the table after the Roosters match in Round 8, I’ll do a lap of Coogee beach in my birthday suit! The Bulldogs’ performance is far more meritorious, and for that matter, so is that of the Titans.

Using the same approach to measuring draw strength, here is how the adjusted period from Round 5 through 8 looks:Draw Strength Rounds 5 to 8 adj

As if the Melbourne Storm needed a good run, right? Along with the Sea Eagles, they have been the best performing of last year’s Top 4, and now both appear to have a rails run into Anzac Day. At the other end of teh spectrum, the Dragons (as noted) and Bulldogs will find it tough to maintain their positions on the ladder, as will the Broncos.

But here’s the thing – the 2014 form guide is so different to last year’s, even the latter half ot the season, that it makes sense to recalculate the strength of draws basd on this year’s form. Looking at it this way, the next four weeks looks like this:

Draw Strength Rounds 5 to 8 2014 form adj

If you thought the Rabbitohs were up against it, check out their draw! It’s the most difficult of any team for the next month, much of it due to having three of their four games away from home, but also in recognition of the form of their upcoming opponents. Sitting 13th now might not be getting a whole lot better in a hurry.

The Warriors didn’t take full advantage of their early draw (surprise, surprise(, and now face a difficult task to tread water if 2014 form continues across the NRL field.

The Titans have done what was asked of them in the first four rounds, and if they can remain in the Top 8 after Round 8, then they are well on the way to securing a finals spot (Origin period notwithstanding).

The bolter here could be the Panthers. Sitting mid-pack and faced with a relatively kind draw (it’s never easy, it’s NRL after all!), it’s not inconceivable that these pokie-playing mountain men will be a Top 4 proposition, and won’t that set the cat amongst the media pigeons. Phil Gould might even go to a game!

When all is said and done, though, I’d expect Manly to be leading after Round 8 from the Storm and Roosters, with a remaining Top 8 that no one would have picked pre-season.

Introducing Positions 5-8 for the NRL Semi Finals … I think

For supporters of the Top 4, you’re ridin’ high and sleepin’ easy. Apart from some possible jostling at the top for the Minor Premiership (and I expect the Roosters to go hard, preferring to play Manly in Week 1), the teams and order is pretty much settled.

For supporters of the Knights, Bulldogs, Sharks, Raiders, Panthers, Warriors and Titans (positions five through 11), there will be a few more anxious moments over the last seven rounds. Sleep will be harder to come by, stress levels will rise, and life will be a little bit less fun. You may even scream uncontrollably at the TV screen on occasion.

Don’t despair. This is why the Dr is here – to provide you with some literary stilnox to solve this problem (and I am aware how that reads …). Then again, I did pick the Cowboys for the Top 4 before the season began, so read on at your own risk!

Surprisingly, even though these seven teams are separated by a solitary game, positions 5-7 appear to be almost straight forward (yes, famous last words). The 8th finalist, however, is harder to pick than a broken nose. Let me tell you who, and why.

Using highly UNsophisticated modelling techniques that cover the form through Round 19 and the upcoming strength of each team’s draw, we can make a relatively simple, yet logical judgement about each team’s fortunes.

Ranking each team’s opposition over the final seven rounds using the Dr’s 11 secret herbs and spices, a distinct hierarchy emerges. Clearly, the Bulldogs have the ‘easiest’ draw, followed by the Knights etc. But look at the difference between the Bulldogs’ draw ranking and the Raiders! 49 vs 72 – that’s quite a hurdle for the Raiders to overcome.Race to the finals

The second column of numbers looks back at the way each team has performed at home and away, and actually how well they’ve performed as measured by their winning margin (1-12 or 13 plus, with losses scoring zero).

The rankings change marginally across the group, but the top two teams remain the Bulldogs and Knights, in that order. Looks like we know who will be hosting the first finals in this part of the draw!

The Sharks have done well enough to rank 3rd and 4th respectively, so on the balance of probabilities (ASADA effects aside), we may well have found our 3rd finalist. I’m assuming we don’t have a Jana Novotna-like collapse here in all cases!

The remaining spot is the one open to more conjecture.

At this stage, the teams most likely to battle out this remaining spot are the Panthers and Warriors. This hurts me to say, in a way, because I always love seeing the Raiders in the finals, but given their run home, it’s going to be nigh on impossible! Having said that, the Warriors and Panthers are just awesome to watch when they get it right, particularly the Warriors.

The Panthers are in an enviable position here with respect to For & Against. They are currently ahead of the Raiders by 91 points despite being a game behind. Further, they are 118 points ahead of the Warriors, meaning as long as they can keep their form up, they can shut them out of the finals.

As far as the Warriors are concerned, For & Against is currently their major obstacle as you can see in the graphic below. Whilst I place them 4th best in terms of their draw ahead of the finals (just pipping the Panthers), their form to this point is the equal worst of this group alongside the Raiders.

The good news for them is that they have hit a rich vein of form now that the ‘structure overload’ seems to have been removed from their game. They need to take advantage of this and simply keep winning to make up for lost time and points, and hopefully throw a huge margin in there somewhere to improve the For & Against, and therefore their chances of squeaking into the Top 8. Who doesn’t want to see the Warriors in the finals?

I noted after the earlier mauling by the Panthers that the Warriors were good enough to turn their season around, and that it was in their hands. Almost poetically, they play the Panthers at home before the finals, and must win that game. It really is in their hands!For and Against_Contenders

The Titans’ draw is almost equally as appalling as the one facing the Raiders, and includes the Warriors, Roosters and Storm on consecutive weekends to round out the season. Along with a performance record so far that is insignificantly different to both the Warriors and Raiders, the door is hardly even ajar for these guys.

So, while the mathematical ruler has already put a line through the Eels, and will soon do so for the Broncos, Dragons, Tigers and Cowboys, the Titans look to the be the first of this group of seven to face the same fate.

How well does your NRL team convert metres into points?

In the pre-Origin lull, let’s slip in a few stats. I’m sure you’ll thank me later …

Looking through the NRL data yields an array of both fairly obvious results, as well as relationships you might not expect. There are certainly some that don’t jump off the page at you until you take a close look and add a good dose of interpretation! I would include the halves percentage of a team’s defensive workload as one of these (covered in a past blog).

Similarly, while the amount of metres a team carries the ball during the game correlates positively to the points they score generally (though not Rabbitohs and Storm, strangely), how does that correlation behave if you take into account the opposition’s metres and points? ‘Net’ differences, in other words.

 As you can see in the examples below, it can cut many ways – the difference in metres gained doesn’t necessarily translate predictably to ‘net points’: Scatter Knights

Clearly, the metres gained matters considerably to the team above when it comes to scoring points relative to the opposition. The relationship is astonishingly predictable, and if you were to tell me this team, let’s call them the Knights, shall we, would have a +500 metre advantage over their opposition in a particular game, I’d expect them to win by about 25 points. Or, a -200 metre deficit would translate to a loss of about 15 points.

Attacking prowess and thrust, alongside defensive techniques and attitude can really dilute this relationship. For a team that doesn’t rely as heavily on possession and territory for their points, the relationship looks more like this:Scatter Manly

Let’s call this team Manly.

You can see that I can’t make the same kind of back-of-the-envelope quantitative judgement based on these results, and the R-squared (a measure of data fit) of 0.179 tells me I’d be a fool to try. It’s almost completely random!

With the Knights, though, an R-squared of 0.915 (where 1 is a perfect fit) tells me I could be quietly confident of the nature of the correlation of net metres into net points.

Unless you’re gambling, predicting what the difference in metres gained will be in an individual game is irrelevant. Its application is better reserved for planning your approach to playing a specific team.

In this case, it would be quite useful for a team playing the Knights. You know that if you take an even share of the ball and translate it to a relatively equal performance in metres gained, then you’re a better than even chance of winning the match. Your game plan might therefore adjust to focusing more on ball control over and above intricate set plays and other aspects of the game plan.

As of Round 15, here are the R-squareds for all NRL teams, showing quite emphatically the teams that rely more on possession and metres in order to outscore the opposition than others.R Squared

The two immediate observations are:

          The Knights’ net points trace an almost unbelievably regular path based on metres gained against the opposition. Their attack is good enough to post a lot of tries, but clearly needs to get a roll on beforehand, and needs a lot of ball. This is one reason why even in the unlikely event they make the finals, they won’t last long.

          Manly and the Storm, as top-4 teams, can win ugly. Even if you are taking 55% of the ball from them and making significantly more metres during the game, they can find a way to win.

The ability to remain in the top-4 based on stats such as these says a lot about the Storm and Manly, and makes them dangerous in a finals situation.

The Rabbitohs are mid-field in this statistical category, highlighting that they are a bit of a mixture. It is worth noting, however, that there have only been three games where they have lost the metres battle this year, the solitary loss coming to the Storm. The worst net metres performance actually resulted in a win against Manly.

For the other top-4 side, the Roosters, their net metres performance is also fairly regular and strong. For a team who have struggled to post points in recent years, this is the year you don’t want to give them a lot of ball and get a roll on.

A not-so-obvious observation is that the data works in reverse too. Net points can also be negative, and there are many teams, like the Tigers for example, that are the complete opposite to the top teams – the Tigers have only had three games where they won the metres dual, while the Rabbitohs have won all but three. Here’s the Tigers’ chart followed by the Rabbitohs:

Tigers:Scatter Tigers

Rabbitohs …Scatter Rabbitohs

Then there are other cases such as the Dragons, who have a habit of winning the battle of metres, but who still have an enormous dispersion of results. Clearly their attack is missing some vital ingredients. They simply should not be losing games with 200-400 metres advantages. The three losses you see below are the difference between their current position and sitting relatively comfortably in the top-8.Scatter Dragons

Anyway, just a few observations.

Enjoy your pizzas tonight, one and all!