Also known as knew-it-all-along effect or creeping determinism, it is the inclination after an event has occurred to see the event as having been predictable, despite their having been little evidence for predicting prior.
Sometimes it is a bias, sometimes it’s people saving face and trying to seem competent. This one is pretty self-explanatory: someone will pretend to having known it all along since the beginning, only when the result is given.
How it is exploited:
This one is tricky, as many biases are exploited together with others. Hindsight Bias can be exploited by taking advantage of Choice-Supportive Bias and the Confirmation Bias.