We hear a lot these days about run metre domination and in particular post contact metres – what if I were to tell you non-contact metres is a better predictor of game margin.
Say Wut?
Yep the run metre metrics you see reported actually has sub-categories. The two most popular are:
- Post contact metres – distance gained after contacting a defender
- Kick return metres – distance carried into defender after kick receipt
“All run metres” includes totalling not only the above sub-categories but also line engaged metres (player has engaged the defensive line or run to a dead end before passing or kicking) and the ‘non-contact’ metres involved in your generic run (ie from where the player received the ball until contact with the defender).
I’m going to call and combine these latter two into a “Non-Contact Metres” (NCM) metric. I have to do this as I don’t have access to “Line engaged” run metre data.
First let’s have a look at Post Contact Metres (PCM) vs Game Margin since round 3 this season.
The above chart shows net PCM vs game margin (net means how many more PCM metres one team ran verse the other) and there is a pretty good relationship with winning or losing (data points in top right and bottom left).
There are some exceptions – notably Manly’s epic defensive effort to hold out Parra in round 10 despite a huge negative differential in PCM. On the other side Newcastle lost to the Bulldogs despite +100m in PCM – this was the game played in pouring rain where they lost both McCullough/Watson.
Overall though you can see why PCM is a highly rated performance metric and worthy of commentary.
How about Non-Contact Metres?
Net NCM also shows a strong relationship with winning/losing with a slightly higher correlation coefficient of 0.59 compared to 0.55 for PCM.
Now let’s be clear I am in no way saying NCM is more important than PCM but surely a metric that has this good a relationship with game margin is worth investigating/talking about?
Maybe there should be more discussion around improving a teams NCM rather than none at all?
For example when in possession generating quick play the balls (Cam Murray), fast leg speed (Nathan Brown), dummy half misdirection (Smith) and engaging defenders before passing it on.
When not in possession should we pay more attention to defensive line speed, effective tackling and trapping teams in corners (I won’t mention slowing down play the balls as this gets plenty of coverage).
In a lot of cases PCM and NCM are inter-related – a strong PCM run can have the defence retreating so on the next play NCM is high. Similarly engaging a defender can put a player half through a hole boosting PCM. The influence between the two would really come to light with play by play data which is something many ‘outside’ analysts are clamouring for.
I like the way NCM makes me think how I might complement PCM – sure I want my team to recruit big boppers and have elusive tackle busting backs who smash out the PCM but maybe I also want players who put others in holes/space? A team with a fast moving defence? A dummy half who can misdirect and provide ball in front?
Rugby League Strategy 