Tell (poker) - Reliability

Reliability

A player's tell gives information only about that player's assessment of his own cards, and hence is reliable only when that player has accurately assessed his own hand. An unskilled player may misread a weak hand as a strong hand and thus their tells will only indicate this misinterpretation.

Players can also make mistakes that may seem like a tell, like fumbling chips out of clumsiness or betting the wrong amount online when clicking the wrong button.