The Welsh red card

Another competition, another controversial decision. A Welsh rugby team, who have won plaudits for their wonderful play throughout the tournament were bundled out of the World Cup in the harshest way possible, on the back of what looked to many like a harsh refereeing decision. Sam Warburton, the brilliant young Welsh captain and a player recognised as someone who strives to play fairly, was sent off in the 18th minute of the game for a clearly dangerous tackle on Frenchman Vincent Clerc. He hit Clerc hard, tossing him over. In his defence rather than carrying the tackle through and driving CLerk's head into the ground he let go as he realised what was happening. Clerk was not badly hurt as a result.

Warburton was shown the red card. At a stroke the Welsh team, who had been largely controlling the game up to that point, had little chance. They spent the rest of the game trying to plug the hole left in their defence. As it was they pushed the French all the way, going on to score the only try of the match and losing by only a point. Surely without the red card they would have won. The final isn't now going to be between the best two teams of the tournament.

Red or yellow?

Should it have been a red card? The pundits in the TV studio, Francois Pienaar, Lawrence Dallaglio and Gareth Thomas were sure it was the wrong decision. Others, like former Welsh captain Robert Jones and French coach, Marc Lievremont claim it was the only decision that could have been made.

Yes it was clearly dangerous but from the replays it was clearly not malicious. The letter of the law may mean that must be a red and referees have no leeway as Robert Jones has claimed. However, very similar, and possibly worse, tackles in other games in the tournament were not red carded. What seems certain is that if this red card wasn't a mistake then those earlier yellow cards must have been.

So what do we do? Do we follow the example of football managers and take every chance we have to berate the referees? People make mistakes. They always will, and referees are always going to be on to a loser if we look for someone to blame. Clearly everyone (referees included) want mistakes to be avoided. Is that possible?

In fact computer scientists have been studying the problem for decades and have come up with some sophisticated ways of preventing mistakes being a problem. Even simple solutions can improve matters in sport though. Whilst who wins a game of rugby is not a life and death issue, computers that make mistakes can kill. That's why computer scientists have put so much thought into it. We trust our lives to computers. They control the brakes of our cars, they fly planes, they put astronauts into space and bring them back safely, we leave them to run nuclear power plants... These safety-critical systems need dependable solutions. The computer programmers may have made mistakes that mean the computer controllers sometimes get it wrong. The people who design the system may not have thought of everything bad that might happen. Human operators of those computers could make mistakes too. Mistakes will happen. The system as a whole has to be designed to protect against those mistakes - even ones we havent thought of.

What matters?

What matters most if problems are to be prevented is that there is a no-blame culture. When mistakes are made we mustn't look for scapegoats, we must look for solutions. Only that way will we prevent the same thing happening again and again. Everyone involved must be part of the solution. Vilifying people isn't going to help. The airline industry has got this right. As they know they won't be blamed, pilots report their mistakes. That means patterns are identified quickly and the software or procedures changed to prevent them happening again.

When a problem has been identified the next thing to decide is whether its consequences are bad enough that it is worth fixing them. Clearly if lives are at stake its worth trying to fix. In other situations the fix might cost more than is gained. Then it may be better to just accept the mistakes.

If the problem is bad enough though the next thing to do is to find a fix. Not a fix for a single incident - so don't just sack the person who made the mistake - but one that prevents anything like that happening again. What are the computer science solutions to protect against a rogue decision? There are lots but let's look at one. A similar situation haunts the designers of the computers that control space craft. These flight computers have to control the space craft getting payloads into space or ensuring astronauts return safely back to earth.

Such highly dependable computer control systems use multiple computers. Space is a harsh place to be. Radiation can easily cause a computer to make rogue decisions even if the software is correct and the astronauts make no mistakes. In a spacecraft, three or more control computers run in parallel. They all see the same data from the sensors and all have to make the same decisions on what to do. They should all come up with the same answer. If one computer has gone rogue for some reason and gets it wrong though, its not a problem because no single computer takes the decision like a referee. They all vote on each decision, and if one makes a mistake the others out vote it. That means two decision makers isn't enough as they may disagree. With three, and one mistake made the right decision is still ultimately made.

Back to rugby

How would all that translate to the rugby red card? First of all, do referees feel secure enough to report when they realise they made a mistake, or does the system encourage them to brazen it out? Do players report when they breach the rules, unnoticed? Is there even a system in place to report mistakes at all? In fact rugby as a sport is far better at this than football. The referees aren't vilified as standard. The powers that be are interested in learning from mistakes. There is room for improvement though - they aren't as good at it as the airline industry.

Are bad red card decisions worth fixing? In sport no lives will be lost if we just ignore this problem. As the Wales-France game showed though, a red card can certainly turn a game. Sport is all about the best team on the day winning. If a refereeing mistake prevents that, then it surely should be fixed. It would also be better for the game to remove the controversy even if red card decisions were always right. It undermines the referees and so the sport as a whole to have people talking about the referee rather than the game itself.

Suppose we have decided red card decisions have such potential to change a game that they absolutely must be correct. Given referees will make mistakes, that means we have to change the way the final decision is made to ensure one refereeing mistake can no longer lead to a player being sent off. By this criteria, having a replay judge decide isn't good enough as that referee could make a mistake: a single error could still lead to the wrong decision. Copying the space craft example we should instead get three referees to examine the replay and vote on whether the player should be sent off. That way there will always be both an unrushed decision made based on the best evidence available, but better still a single mistaken referee could not derail the decision.

Controversial refereeing decisions undermine sport, but referees are human so there are always going to make mistakes. That means we must design refereeing system so that single mistakes aren't a problem. That doesn't just mean bringing in technology solutions like replays and goal-line technology. It may mean changing the way that decisions are made. Rugby has a history of learning from its mistakes. Let's hope that by the time of the next world cup that has happened and the system has been changed so that red card decisions are sure to be uncontroversial. Let's hope Wales then do get the chance of playing in the final as they deserve. I hope too that Sam Warburton will still be captain, but a captain who has also learned from his mistake, and as a result is a better player. That way his sending off this time may even lead to him lifting the trophy next time.