TOKYO, 10 Oct - Behind every team at Rugby World Cup 2019 there is a group of exceptionally smart people dissecting the opposition's attack and finding weaknesses in their defence. For USA, Jimmy Harrison is leading the battle of the brains.

The job of an analyst involves long hours spent watching footage of rivals, trying to work out what they are likely to do, something the All Blacks, for one, have obviously taken on board (see above). 

"We look for trends in the data and then we see whether those trends are still true close to the game we are playing," Harrison, right, said. "Sometimes just knowing the trends is not enough, though. Against England we knew about George Ford's show-and-go but we still could not stop it because he's a world-class 10."

The value of filming games and watching them back is that we are poor at remembering exactly what happened during play.

"Not filming games is like taking a test and then just throwing it away. You need that data to show players what they got wrong and what they got right. A coach will think he saw the entire game. When he watches it back, he might realise we actually only got 10 per cent of this right, when he thought we were really nailing it."

With Harrison placing such importance on filming, we decided to watch three clips featuring USA and Argentina.

The first clip was a USA attack against France. How much was pre-planned and how much invented on the spot?

"We have set launch plays and that really helps get us into our shape. For the first few phases the players knew what was going to happen but they do have options to play what is in front of them. For the first play, we are just trying to gain momentum and get over the gainline to set things up for later.

"In the second phase, the players know who will make the carry and who the options are, but the players will need to change that if someone trips or gets involved in a breakdown.

"For the third phase, we have options on either side. If AJ Macginty or Shaun Davies sees that France have over-committed to the right side of the pitch there will be a call so they can change it and reverse direction.

"Marcel Brache has the option to carry, to pass back inside to Joe Taufete'e or to pass out the back to AJ on the fourth phase. We try to give him that triple-threat option.

"In the fourth phase, AJ noticed the guy dropping back, read what was in front of him, and he made a great pass."  

This World Cup has seen a rise of the deliberate overthrow. Instead of throwing to a lifted player in the lineout the hookers throw straight over the top to the midfield. Taufete'e has shown his rocket arm in USA's warm-up match against Canada. The hooker threw almost to the middle of the pitch to set up the American attack. Against Argentina, England did something similar.

"The lineouts are a massive attacking opportunity as there is so much space. If you can get over the gainline it gives you so many more options for the second and third phases. We want to make sure we are constantly changing up our attacking looks so we are not tipping off the opposition.

"If you get all the different attacking plays together and they are the same it is really easy to know what the team will do. In this example, it is pretty smart of England to have Joe Marler in some lineouts and out of others. The defence then have to second-guess the attack. Are they going to overthrow, are they going to get Marler to carry, are they going to go back in the other direction on the second phase, are they going to maul in the middle of the field?"  

Argentina's lone try against England came from some creative lineout work. Argentina had winger Santiago Carreras at the front of their lineout. After some intricate midfield play Carreras re-emerged to break the line and put fellow winger Matias Moroni in for the try.

"Argentina have a very good lineout, and they have great guys who can throw the ball deep and they can get beyond the 15. That is very hard to defend. We really emphasised keeping connected with our 10s and our defender at the back of the lineout. Mako Vunipola was in position to make this play, it was just a missed tackle.

"It is a mismatch as well, a winger against a front-row forward. It is run perfectly by Argentina, once they get that back ball they have so many options on their attack where they are lethal. As you can see, they were beating a world-class defence like England on first phase. Disrupting that lineout ball and staying connected at the back of the lineout is vital because we know they do attack in that space."

Next time you watch a game from RWC 2019, look for the analysts peering at their laptops in the coaches' box. They spent the week preparing their players for what to expect, and will spend 80 minutes hoping they got it right.

RNS sl/sdg/co