Duckworth-Lewis-Stern method (DLS) will probably be used today in this rain interrupted match.
This has to be the most complicated mathematical formula used in sport. Most followers, like me, don't understand it.
Its purpose is - when the overs have to be limited, because of the weather - to determine the run target for the team batting second.
Essentially based on the number of runs scored by the runs scored in the first innings - and taking into account the time left for play!
Obviously, this has to be fair to both sides - and the cricketing authorities had to enlist the assistance of mathematical experts and academics.
Duckworth, Lewis and Stern were those very smart chaps.
DLS's raison d'etre is to reduce the number of draws - given when the the team batting second couldn't have the same number of overs, as the first.