LAS VEGAS — For much of Buster Posey’s first season as the Giants’ president of baseball operations, the focus was on simply watching and listening. Posey was a regular in the Giants’ dugout during batting practice, often sitting on a folding chair in the back corner and observing workouts as he chatted with any coach or team leader who would stop by. Despite having four young children, he was a presence on road trips. The entire front office gathered in the same city multiple times, giving Posey a chance to listen to not just those who work at Oracle Park, but also the player development staffers from Arizona, international scouts based in Latin America, and members of the amateur scouting group.Posey learned that there’s value in pushing a rival exec to complete a surprise trade in June, and also that there’s danger in extending a contract before you’re 100 percent certain. He saw how deadline plans can go up in smoke over the course of a bad homestand. He watched the lineup complete thrilling comebacks, but also go into slumps that were hard to watch. But mostly, Posey discovered the same lesson as everyone else who...