Pitching ERA

Pitcher's ERA is not the best way to measure performance. A pitcher with lots of run support need not be so careful. So, the first interesting statistic would be ERA minus average run support. The second takes into account variance of the two statistics and estimates the probability that the difference is positive. The third takes into account the opposing pitcher's ability, estimating the expected run support for each particular game.

They say solo home runs don't hurt you very much. What happens if you subtract solo HRs from ERA? Who has the largest and smallest percentage of ERA as solo HRs? Ratio of solo vs. total HR?