With the change from low-roll-wins-ties to high-roll-wins-ties, the probabilities in the How Good are Masteries? section p. 33 are no longer accurate.
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With high-roll-wins-ties, a one mastery advantage wins about 95% of the time rather than 75%. To illustrate this, consider the example of cottar 10 vs. thane 10w1.
With low-roll-wins-ties, cottar wins when cottar succeeds (50%) and thane fails (50%) = 25%, because the roll that gave the cottar success also gives him the low roll.
With high-roll-wins-ties, all of those cases go to the thane: the roll that gave the thane failure also gives him the high roll. So the cottar only wins if:
(a) cottar crits (5%) and thane fails (50%) = 2.5%
or (b) cottar succeeds (50%) and thane fumbles (5%) = 2.5%
= 5%.
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The “all but certain to win” text then applies to a 2-mastery advantage rather than a 3-mastery advantage.
Likewise, the “will always be victorious, although” text then applies to a 3-mastery advantage rather than 4.
