The International Cricket Council (ICC) introduced the concept of a supersub into One-Day cricket last July. The plan was that a team can name a 12th player and replace a member of the starting eleven by the 12th player at any point of the match. The wanted to try this out for a year and see how it works out.
It was a good innovation and definitely gave teams more options. But there was a catch. The teams were required to announce the supersub before the toss. Now clearly that is disadvantageous to the team losing the toss: if you go with a bowler (batsman) as the supersub and are forced to bowl (bat) first then you are effectively not using the option of a 12th player, and the team winning the toss has potentially twelve players against your eleven. This is a brilliant analysis of how the supersub rule favored the team winning the toss.
It is clear that the ICC can not continue with this rule as it stands right now. They either have to scrap it altogether, or at least allow teams to choose the supersub after the toss is decided.