Take the dude from “Taxi Driver” and make him a middle-aged knife salesman with a passion for the San Francisco Giants and their star player. Now make the plot as implausible as humanly possible. Out of the hundreds of people I know in professional baseball, not a single one likes “The Fan” (1996). And we’re talking about a film with De Niro, Snipes, Barkin, Del Toro, Leguizamo and, um, Kruk. The friction between fans who take things too seriously and players who don’t take things seriously enough should make a great story. Instead, it strikes out. Just like that pun.