Find the probability of someone winning for deals 1 through 6 ...
Also, note that Deal #7 MUST be a win if it gets that far.
[Note: multiply by 2 because either player could win]
Now, moving on to the the second deal, this assumes the first deal neither player won.
The table below summarizes the probability distribution and the expected value for D which is equal to approximately 2.5 deals
Hope that helped!