[...] it goes in baseball’s messy arbitration process. Belt on Friday formally filed a request for a $7.5 million salary, more than doubling the $3.6 million he earned last year, according to arbitration maven Jon Heyman. A panel of three arbiters would hear arguments from both sides and pick one salary or the other. The Giants have not gone through an entire arbitration hearing since 2004, when new catcher A.J.