The Giants don't have a bonafide closer. They do, however, have several quasi-closers who have filled that role in the past, or possibly could do so in the future.
Will Smith, Mark Melancon, Sam Dyson, Tony Watson and Reyes Moronta have combined to post a 1.82 ERA and 1.03 WHIP in 39 2/3 innings, giving San Francisco what ranks as one of the best bullpens in all of baseball. The Giants' relievers rank first overall in WAR (plus-1.6), according to FanGraphs.
With the emergence of Trevor Gott (plus-0.