managing those investments was a key reason that Yahoo’s board hired Ms. Mayer. Mr. Loeb had accused Yahoo’s previous leaders of mishandling both their core business and the Alibaba relationship.... Ms. Mayer delegated the Alibaba issue, hiring an experienced dealmaker, Jacqueline Reses, to be the company’s principal liaison to Alibaba and its leaders, Jack Ma and Joseph Tsai. Ms. Reses helped the Chinese company navigate its initial public offering. She also renegotiated an agreement, struck just before Ms. Mayer arrived, that would have forced Yahoo to sell an additional 122 million shares in the offering. Those extra shares are now worth $15 billion.