To win a test match it is necessary to bowl the opposition out twice. The sufficiency is provided by scoring an additional run. A test match can be won without taking 20 wickets when the losing team declares in one or both innings. It can be argued that the losing team did not do enough to win the match. The win was earned nonetheless because losing team terminated both its innings and winning team scored that extra run.
A limited overs match is won by scoring that extra run using the same number of allocated overs. The number of wickets to fall play a limited role. If a team is bowled out without using all the available deliveries then it forfeits the remaining deliveries. Whether it lost no wickets or 9 at the end of scheduled overs does not make any difference.
Should number of wickets play any role in the margin of victory? S Rajesh raised concerns about Net Run Rate as a tiebreaker here during Group stages of ICC Champions Trophy 2013. In a low scoring thriller team batting second can win a match with plenty of overs to spare without many wickets in hand.
Net Run Rate works most of the times. It has its limitations and two alternative measures are Run Difference and Ball Difference. Run Difference is proposed by Duckworth & Lewis. The winning margin by runs for team batting first is available. In the other case a mathematical score can be derived for the team batting second based on number of overs and wickets remaining.
D/L method is used in case of interrupted matches. There is an obvious problem with Net Run Rate when one or more matches are interrupted which did happen during #ct13. In this tournament two matches were 22 & 24 overs long instead of 50. The tie-breaker is calculated based on actual deliveries and actual runs but some matches are longer than others.
Ball Difference advocated on this site is always computed for the total available overs in a limited overs match. It does not mix the “RUNS” scored in a high scoring match with a low scoring thriller. ‘1 RUN’ victory when both teams score 300+ is not equivalent to ‘1 RUN’ victory when both teams fail to reach 150.
D/L or VJD or any other model used to determine the outcome in a truncated match is a model. These models have improved in the last decade and should improve in future with a scope for another model. The margin of victory based on these models will return a variable value for the same completed match based on the version used.
Ball difference is extremely elegant. Every dot ball, every run saved will be appreciated, valued and cheered during the match if this system is used as a tie-breaker. In a crunch game players, viewers and commentators will know exactly what is needed to qualify in advance and during the match.