McGrath by the barest of margins. Could go either way imo tho. Marshall looks better in some of the basic metrics used to evaluate a bowler: average, SR, WPM, % of fifers. However McGrath is better in important factors as well: % of top order wickets, longevity(in terms of matches and wickets taken), and the fact that the last 6 years or so of his career was one of the easiest eras for batting and his stats in this era are genuinely insane(Marshall has terrific performances on flat wickets as well, but the only places he faced flat wickets were India and to some extent Pakistan, in McGrath’s case during the second half of career he faced such wickets on a much regular basis, especially considering his home wickets had become quite flat). I tilt towards McGrath, because I think in some of the factors Marshall beats him, it is very marginal such as average(diff of less than 0.7), WPM(difference of 0.06). The metrics(from which I have listed)in which Marshall is clearly ahead are SR and % of fifers. But McGrath is far ahead in % and number of top order wickets(top five ever, while Marshall is clearly further down the list), longevity(nearly 1 1/2 more matches and 180+ more wickets), and the era in which the second half of his career was in. Plus McGrath’s domination of the two best batsmen of his era edges it very very marginally towards him( Marshall also dominated Gavaskar and Border, but they weren’t as good as Tendulkar or Lara, and Marshall never bowled to the best batsmen of his era- Viv Richards).
