Hanigan may be one of the most overlooked contributors on this team.  While Murphy is one of the best rated catching prospects and Wolters has done well, it seems to me that Hanigan's veteran presence and baseball smarts have been instrumental in all four rookie pitchers' success this year.  I haven't looked up the stats in all the games, but it seems like when Hanigan is behind the plate the rookies go 6 innings give or take 2/3 with giving up only 2-4 runs.
I don't think he gets enough credit.