OK, here you go: (From MLB Official Rules: 10.00 The Official Scorer)
10.18(h) A relief pitcher shall not be held accountable when the first batter to whom he pitches reaches first base on four called balls if such batter has a decided advantage in the ball and strike count when pitchers are changed. (1) If, when pitchers are changed, the count is 2 balls, no strike, 2 balls, 1 strike, 3 balls, no strike, 3 balls, 1 strike, 3 balls, 2 strikes, and the batter gets a base on balls, charge that batter and the base on balls to the preceding pitcher, not to the relief pitcher.