BA neglects the offensive value of the base on balls and assumes that all hits are created equal. But our love affair persists. Similar to a pitcher's Control ratio. At the other end of the scale are ratios less than 0.50 which represent batters who likely also have lower BAs. A measure of a pitcher's raw ability to get the ball over the plate.
Command is one of the best gauges to use to evaluate minor league performance.
Baseball's upper echelon of pitchers will have ratios in excess of 3.0. The variance between a pitcher's ERA and his XERA, which is a measure of over or underachievement. A positive variance indicates the potential for a pitcher's ERA to rise. A negative variance indicates the potential for ERA improvement. Discount variances that are under 0.50.