Wednesday 5 January 2011

Tie-breakers

Short post tonight, as I'm in the Far North of New Zealand, a place with no RadioSport, and very limited internet accessibility. (On the plus side I went out on a beach and gathered some shellfish today, and saw my first ever weasel!)

For a long time in the deveopment of ODI's to the current form, there were many different methods used to decide the results. Methods were used involving run rates, removing the lowest overs, etc. All of them tended to provide skewed results.

Then Duckworth and Lewis came up with their method of calculating targets and results in rain affected matches. While it took a while for everybody to agree with it, eventually the fairness of their system won over most of it's critics.

However a similar situation is still happening, but without anyone really noticing it. The net runrate (NRR) system seemed to me to be the fairest method of tie-breaker between two teams that have the same number of wins in a tournament. However I'm no longer so sure.

I have a couple of situations that might suggest that a better situation is needed.

Game 1:
Team A scores 144 all out in 31 overs on a green pitch.
In reply Team B scores 145/9 off 35 overs.

The NRR for Team A after their win is 1.323, and -1.323 for Team B.

Game 2:
Team C scores 225/2 off their 50 overs.
In reply Team D struggles to 185/7 off their 50 overs.

The NRR here is ±0.8

Is this fair? Is game two closer than game one? I personally don't think so. I would prefer to use a system based on resourses remaining. Perhaps an adaptation of Duckworth Lewis for this situation would be a better idea.

1 comment:

  1. Just to clarify: The NRR counts the overs used as 50 if a team is bowled out. This means that Team A would have their run rate calculated as 144/50 of 2.88. Team B would have their run rate recorded as 145/35 or 4.143. That is why the difference would be so much larger in these cases.

    There is likely to be at least one upset in the World Cup, and one bad NRR result could make a very big difference to the outcome of the World Cup for a team.

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