This is what I use to display a map with 3 pins/markers:
I think you have to calculate latitudine min and longitude min: Here is an Example with the function to use to center your point:
//Example values of min & max latlng values
var lat_min = 1.3049337;
var lat_max = 1.3053515;
var lng_min = 103.2103116;
var lng_max = 103.8400188;
map.setCenter(new google.maps.LatLng(
((lat_max + lat_min) / 2.0),
((lng_max + lng_min) / 2.0)
));
map.fitBounds(new google.maps.LatLngBounds(
//bottom left
new google.maps.LatLng(lat_min, lng_min),
//top right
new google.maps.LatLng(lat_max, lng_max)
));