Anchors

Poker is partly a game of card distributions and partly a game of psychology. The card distribution aspects of the game can easily be straightforwardly modeled via rather simple mathematics (even if if might be computationally complex). The psychological aspects are often not so straightforward.

One of the psychological complications is the concept of anchoring.

Anchoring and adjustment is a psychological heuristic that influences the way people intuitively assess probabilities. According to this heuristic, people start with an implicitly suggested reference point (the "anchor") and make adjustments to it to reach their estimate. A person begins with a first approximation (anchor) and then makes adjustments to that number based on additional information.

Anchoring can manifest itself in many ways in poker, the most prevelant is the tendency to use pot size as an anchor in determining bet size in no limit poker. Bhy manipulating the pot size we can effect the tendency of our opponents to pick a bet size on future betting rounds. Anchoring our bets on pot size has become so common in poker that it seems natural.

It's a tendency that can be manipulated -- not just by manipulating the pot size, but by manipulating the physical size displayed by the number of chips. By using larger denomination chips we might make the pot seem smaller to the opponent. Using a green chip ($25) in a red chip ($5) game might do that. But using a black chip ($100) in a red chip ($5) game might have the opposite effect, the unusually large denomination might have the effect of making the pot seem huge.

One thing you can be sure of -- your bet denomination choices will effect your opponents future behavior, even if you can't be sure what that effect is.

A Computer Scientist in a Business School has some examples of anchoring.