[Ringmaster]

Suppose p = probability villain folds.

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Bluff all-in betting $160 to win $103

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EV = p(103) - (1-p)(160)

set EV = 0 and solve for p to get:

p = 160/263 = 60.8%

[ QUOTE ]
Bluff $80 to win $103

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Using the same logic as above we get:

p = 80/183 = 43.7%