How do the Microsoft and Yahoo boards compare?

Taking the performance of other companies that Microsoft and Yahoo's outside board members direct, Portfolio's Russ Mitchell has calculated the "plus-minus" for the respective players, as a hockey statistician might say. In other words, have the public companies that share directors with Microsoft and Yahoo gained or lost in an otherwise down market? The Microsoft camp has actually beaten the market, posting a 4 percent gain with six directors enjoying share price gains in other companies, while the Yahoo camp is well behind, posting a 22.5 percent loss, with six directors sitting on stock losses.