it depends. If the bases were loaded and a batter walked, that would effect the earned run average. But if a batter walked but it did not effect the score, it would not effect the pitcher's earned run average.
Generally yes...if a pitcher walks a batter and he comes around to score, that is an earned run against the pitcher, unless he scores on an error
Bases loaded walks that score a run also count as an...
It is a measure to judge how effective a pitcher is. If it calculated by taking the total earned runs a pitcher has allowed and dividing by (total #of innings pitched/9). Giving you an average number...