Most Productive Overs method
The Most Productive Overs (MPO) method was a mathematical formulation designed to calculate the target score for the team batting second in a limited overs cricket match interrupted by weather or other circumstances.
MPO was used most notably during the 1992 Cricket World Cup, and the controversial effect of its application during the England v South Africa semi-final directly led to the development of the current method, the Duckworth-Lewis method.
The Average Run Rate method was replaced in 1991 by the Most Productive Overs method, having been developed by Australia after the third 1989 World Series final between Australia and the West Indies.
Chasing Australia's 226/4 off 38 overs, the West Indies needed 180 off 31.2 overs when rain stopped play for one hour and 25 minutes. Under the average run-rate method, the revised target was 108, meaning the West Indies needed 61 off the 11.2 overs that remained. The West Indies won the match and the competition with 4.4 overs remaining and eight wickets in hand. Australian fans booed this unsatisfactory conclusion, which was criticised by the media and Australia's captain Allan Border.
In this match, the later Duckworth-Lewis method would have increased the West Indies' target to 232 to take into account a two-hour rain delay during Australia's innings, and then revised the target to 139 after the second interruption.
If an interruption means that the innings of the team batting second is reduced to a total of X overs, their target score is adjusted as follows:
Whereas the Average Run Rate method heavily favours the team batting second (Team 2), the MPO method only favours the team batting first (Team 1). 
The flaws in the method are:
- It effectively penalises Team 2 for good bowling by ignoring their best overs in setting the revised target.
- The method takes no consideration of wickets lost, but how Team 1 scored their total.
- Substantial bookwork is required by the umpires and officials to determine the revised target.
- If the least productive x overs were maiden overs, Team 2 would be left in the position of matching or beating Team 1's actual score, but with fewer overs to do so.
Two subsequent modifications were used: resetting the target based on the x consecutive most productive overs of Team 1's innings (where x is the number of overs Team 2 is to face), and reducing the target by 0.5% for each over lost, with the target given by the next highest integer. These modifications reduced Team 1's advantage, but they failed to address the intrinsic flaws of the method.
- Duckworth/Lewis, Q2. "The D/L method: answers to frequently asked questions". ESPN Cricinfo. Retrieved 16 September 2017.
- 3rd Final, 1988/89 Benson and Hedges World Series Cup
- Duckworth, F.C.; Lewis, A. J. (1998). "A fair method for resetting the target in interrupted one-day cricket matches". Journal of the Operational Research Society. 49 (3): 220–227. doi:10.1057/palgrave.jors.2600524.