From a reader:

In recent years, work has been done, by Bill James and others, which highlights the huge importance of the base on balls. Ignoring McGwire’s prolific walk rate is simply absurd. McGwire is 78th all time in On Base Percentage (at-tip Baseball Reference, the best baseball site on the Internet). When you remove players who mainly played in the 19th century and played fewer than 10 seasons, McGwire jumps to 60th. OBP is a stat that is not highly affected by power (McGwire was intentionally walked more because of his power), but even in down years for power, he had a very good batting eye. By On Base Plus Slugging, OPS, a general stat which better encapsulates offensive performance, McGwire is 13th all time. By Adjusted OPS, which removes McGwire’s advantage for playing in such a strong offensive era, McGwire is 11th all time. If you ignore steroids, it is obvious that McGwire is one of the top 15 offensive forces in baseball history, and a deserved Hall of Famer, despite poor defense and baserunning.