Oom’s analysis: Why Japan won’t win

In his debut for SA Rugby magazine, OOM RUGBY outlines the numbers behind the Springbok defence and why Japan won’t win.

Hi guys. First off, apologies for my English, it is my third language after Rugby and Afrikaans.

The Bok defence is a new animal in some ways. Yes, there is nothing new about aggressive linespeed, but it is the way the Boks does it that is pushing the envelope right out of the post office. If the Boks does win the World Cup, it will be because of their defence.

So, it is quite ‘poetic’ in a way that we meeting the incredible Japanese team in the quarters-final, because they a team that in own way is reinventing the game in the wonderful way they attack. The only problem is that this attack is specifically not geared to deal with the Bok defence. Let us take a look why!


The Bok defence is unique in world rugby. It is brutal and suffocating but in the essence it is quite simple. For the players there are a focus on execution and not complexity. The coaches doesn’t want players thinking too much, they want them to focus on DOING. The Bok defence don’t have many option trees, so our players is not judged by the decisions they take, they judged by how they execute.

1.Trigger on the ball 2. Get off the line 3. Stay square 4. Read 5. Don’t get compressed and narrow

In the picture above we see the whole Springbok line get up fast, read receivers, ‘swim’ past decoys, and attack remaining carriers. Maybe we can coin a phrase that while other teams has more complex systems where they ‘read & then speed’, the Boks is a team who is more ‘speed & then read’. This focus on acceleration mean the Boks get up into opposition lines earlier. So they catch you deeper, make a hit, or force play back inside, or force a mistake, or force a early pass. Because of this, the wider you try play (and the deeper you stand) the more the Boks can hurt you.


The data guys at Rugby Analytics backs this up and tells us that teams who has tried to set targets with more width against the Boks has suffered the most. For instance, in the Springboks draw over New Zealand in Wellington in June the Kiwis had a average target width of 15m from the rucks. (It is the average of all the places that New Zealand attacked the Boks). We saw how their attack could just not get going. The picture below is a classic example from that match where Barrett get hunted down deep behind the advantage line and the Boks take the All Black options away.

The problem for Japan is that they like to play with width (or more accurately, variation). Like most teams they will set up closer carries and pods, but then they also like to often hit wider channels. Rugby Analytics tells us that in this World Cup their average attack targets is over 11m from rucks. This will play right into the Springboks hands, as it is exactly the kind of play and variation that the Bok defence is designed to kill.


But it all come down to linespeed and the ability to sustain that linespeed in a match. Ireland and Scotland lost to Japan because they eventually allowed the Japanese tempo to dictate … How passive was Scotland on defence? Rugby Analytics shows us that the Scots lost a total of 135 metres in defence! Meaning that if we add up the gain after every Japanese carry, Scotland actually went backwards. Below we can see the Scots standing off, letting the Japanese run at them and develop play.

The Boks has no problem in this area. They have shown to not only have the most aggressive but also the most consistent linespeed. Rugby Analytics tells us that against New Zealand in the pool game the Boks actually gained 84m in defence over the course of the match. How do they do it? Well linespeed don’t work by itself … it go hand in hand with slowing down the ball at the tackle area. Because when you slow down your opponent’s ball, it give your defence time to set, line up, and put on their sprinting takkies.


So, the Boks is a team who like to interfere a LOT at opposition breakdowns. Rugby Analytics says that during this World Cup teams has on average attended 41% of opposition rucks, while the Boks has attended 66% of opposition rucks. That is a lot! Two out of three times the Boks will be busy at the opponent’s tackle point … And more than that, the Boks is also showing great accuracy here, with 49% positive outcomes (winning a turnover, or winning a penalty for holding on, or slowing the ball, or forcing extra defenders to join and clean). The competition average for positive outcomes at opposition breakdowns are 41%. It is important to note that the focus is not to poach the ball, it is firstly to slow the ball or make the opposition commits more players to the ruck to protect it.


So if the Springbok linespeed is dangerous, and trying to play wider can get you in trouble, then one of the answers against the Boks is to play narrower. This way, the rush have less time to develop and your close carriers can meet the Bok defenders at the gainline. After New Zealand drew against us when they played with more width, they then played much narrower in the World Cup group game that they won. Their narrower play allowed them to build some momentum and from there they could get quicker ball and find space.

But the problem for Japan is if they do try to play narrower then they will run into a storm that they not equipped to handle. The Boks puts a premium on executing dominant tackles and the Japanese just does not have the carriers to go up against this. According to Rugby Analytics the average percentage of tackles that are dominant at the World Cup is 43%, but the Boks is sitting at a 76% dominant tackle rate. This is not a game that Japan can play if they try to take us on inside …

Dominant tackles are where you start to slow your opponent down and it is a crucial part of setting up eventual linespeed. For the Boks, it is a especially important element, so they put a premium on being able to sustain intensity by having a second pack of tight forwards on the bench.


So, the Japanese is caught between a rock and a moer of a hard place. They can not take us on in the narrower channels, but if they go wider then that play directly into our hands. It is a completely different story to the loss in Brighton because the defensive picture is so different now.

This bring us to the kicking game, which will be Japan’s best chance at upsetting the Boks. Because the Bok wings bite in to help kill play, a flat hard Kick Pass to players waiting on the touchline can get cause trouble. The second type of kick we will see is the Late Kick from midfield, where the Japanese can kick into the space behind the wing after he has been triggered to shoot up. The final type of kick I believe we will see (and in my opinion it is the Boks’s biggest Heel of Achilles …) is if the Japanese backs plays flat, and they put a shallow Stab Kick through the oncoming defenders.

Although my gut say this is what we will see, the truth is that Japan is not really set up to play this way and does not actually play this way. Rugby Analytics tells us that the Japanese flyhalf Tamura for instance has only executed a total of 10 attacking kicks so far in the World Cup. But, if anything, we know that no team works harder than Japan, and that they have among the most tactically clever coaches in their staff … So maybe we will see a variety of little kicks to surprise the Boks on Sunday, and we can trust the Japanese to show the world a different way to handle the Bok beast.

Cheers guys, and enjoy the game!


Photo: Steve Haag via Hollywoodbets