Bench Sumo involves a lot of luck. The MCP statistics try to strip away as much of good and bad luck as possible to determine who actually made the best picks in a basho.
The MCP stats order all BS line-ups from all divisions on a daily basis. If you have the best line-up of the day you get a daily winning percentage (DWP) of 1.000. If you have the worst line-up of the day your DWP will be 0.000, and if most likely your line-up is somewhere in between you will get a corresponding DWP.
From the daily presented table you can see that the third column from the right indicates your DWP. The MCP Score adds all these DWP's over the basho. The whole table is sorted by MCP Score, so on top sits the player who is currently the best (or most competitive) of the basho.
The current MCP Score is the second column from the right.
Finally, you can compare your MCP Score to the number of actual wins (which is indicated in the last column). If your MCP Score is higher than the number of wins, it means that you have had bad luck so far, if it is lower than the number of wins, you can call yourself on the lucky side.
Each day these standings plus some extra information will be presented: