For a calculation, I need to know the symbol content of the average pitcher. I did the starters and relievers separately, using the ABL pitchers. Say that of 53 likely ABL starters, 19 have a B symbol. That means that the average starter has 19/53 (0.36) of a B. The chart below shows the averages for all the symbols. Starters & relievers are combined in a ratio of 7:2, to estimate the pitching over an entire game.
Starters & relievers are quite comparable in terms of the walk symbols, B & L. Relievers have a definite edge for the runners-on symbols, R & H. Not surprisingly, only relievers have Fs.