I'm not going to paste this article because it has graphs, it's too long and I'm not sure but that would be breaking the rules but the link is above.
This is not hardcore stat anlysis but a fascinating look at how speed affects a pitcher's effectiveness. There are a couple of fascinating suppositions - in the right zone an 86 mph fastball is just as effective as a 96 mph heater. Unless a guy throws upper 90s as in 97-98 there doesn't appear to be much difference IN THE LOW ZONES, especially the outside corner. Fastballs improve a pitcher's effectiveness as they rise but their overall value decreases, too. Meaning in the center of the zone a 96 mph heater is markedly better than a 86 mph pitch but still a poor pitch in relation to runs above average. Also, the finding that fastballs receive MORE ball calls when actually in the strike zone per PitchF/x increasing in ball called rate as the velocity increases. - Hence Volquez at 97 on the lower corner will get more balls called there than Arroyo at 86. Possibly a reason young fireballers have more command issues - umps tend to be calling more balls when they ARE in the zone. Found it fascinating. Hope others do too.