It seems true of all the starters. I know it can't be true but it seems like every time the other team has a crooked number you can look back and see at least one walk as a key to the damage. I am not as infatuated as some with strikeouts. I do hate the walks. Doesn't seem like it should have this much impact but if Perez keeps it to 2-3 walks per 9 he is fine and just not very good when it is at 4 walks per 9. I guess if extra walk scores every time it adds 1.00 to his ERA.
I dont think it's so much the actual walk, as what the additional walk(s) say about command.
If you're missing outside the strike zone, you're most likely missing inside the strike zone as well. And those pitches down the middle are the ones that can really cause damage.
Last night, for example, the leaded walk in the 5th hurt, but no more than a lead off single. It was the cookie to Cuthbert that really did the damage. If that pitch is on a corner, it's a lazy fly out.