Bridge, is designed to act as entry node (guard). There is no difference as far as number of hops with or without bridges when you connect to a given server. If there were three hops required to connect to given server without a bridge, there are three hops required to connect to a given server with a bridge. This include the bridge as a first of three hops and two other hops. If only one hop was required to connect to a given server, then if you use a bridge, it will be the only hop. If six hops is required to connect to a server (hidden services), and you use a bridge to connect to the server (hidden services, the bridge act as first hop and you will go through five other hops for the total of six hops. In summary bridge will be your guard.