Baseball: Walk & Earned Run Attribution - Who Gets the Credit?

Question
A pitcher pitches 2 balls to a batter.  That pitcher is then replaced by another who proceeds to throw 2 strikes and 2 more balls, thus walking the batter.  To which pitcher is the walk charged?

And I'm sure that answer will also answer this one.  That same batter/runner eventually comes around to score (no errors).  Which pitcher is the earned run charged to?

Thanks.

Answer
Good question.  With a walk, since an even number of balls are required to earn one, the pitcher throwing the last 2 will be charged with the walk, and subsequently, the run if the batter were to score. A strike out is a little more cut an dry.  Whoever gets 2 of the 3 strikes would get credit for the strike out.  The same rules would apply for a substituted batter.  Whoever gets the most strikes for a strike out or the most balls for a walk would get credit for the strike out or walk.  In the case where two different batters got 2 balls for a walk, the batter getting the last 2 would be credited with the walk.  I hope this answers your question.