The Giants and Dodgers enter their three-game set to end the first half on different trajectories. San Francisco (51-43) bounced back from its worst stretch of the season and has won six of its last eight games, catapulting back to second place in the NL West. Los Angeles (56-38), by contrast, has lost six straight after being swept by the Houston Astros and Milwaukee Brewers. Manager Bob Melvin, though, isn’t taking much stock in which team is surging and which team is slumping.