[quote:b59b6a43c3]a) Why would a CF with a -5 arm not be more dangerous to base runners than a CF with a +1 arm?
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The aggressiveness setting means do you still run or run more even with a lower % chance of success. A -5 arm will decrease the runners' chance of success by 30% over a +1 arm. So it's not that the arm in more dangerous. It's the manager's tolerance for risk or willingness to make outs on the basepaths that is affected by moving the rating.
So for trying to score, "Normal" might mean "will go on a 70% chance to score with 1 out or less, and a 40% chance to score with 2 outs". It's definitely situational. "Aggressive might decrease those levels to 60/30, for instance. So you should not be more aggressive depending on OF arms, it should be purely based on hitter or pitcher park IMHO.