I consider Mike Caro’s book on tells to be a classic and I wholeheartedly recommend it to everyone. However, I disagree with the emphasis he placed on whether a tell was from an “actor” or from a “non-actor”.
In his book, Caro split his tells up into two primary sections: Tells from Actors and Tells from Non- Actors. He said players who act either weak or strong will usually be the opposite of what they are representing. This is a fundamentally true observation but, in my opinion, this idea is only really of much use if you’re playing with very bad players. Most players in mid- to high-stakes games are not actors—their most common tells don’t come from them trying to put on an act; their tells come from them accidentally exposing their level of anxiety or relaxation.
The main problem with focusing on whether a tell is “acting” or “not acting” is that many tells don’t easily fit into one or the other category. For example, many players, when they have a strong hand, will avoid looking at the person whose turn it is to act, and avoid looking at the action in general. Why are they doing this? If it’s a beginning player, he might be actively trying to trick you into thinking he isn’t interested in the action. His actions may be exaggerated. He may actively try to look bored. He may stare off at the television. But you will see decent players perform this tell sometimes, and they are not trying to act. They are reacting to a natural, subconscious instinct to look unassuming. Their tells will not be exaggerated, but will be subtle.
Another example would be players with strong hands who slump in their chair very slightly, making their body smaller. You can see experienced players exhibit this tell. It’s a natural animal instinct to become less threatening when you don’t want to scare your prey—hence the ducking down and becoming smaller. But, again, on the surface it might seem like a conscious act designed to deceive.
There are many human behaviors like these that blur the line between conscious and unconscious. This makes thinking about acting vs. non-acting an impractical way to think about tells. It’s especially impractical because it’s usually only with the most beginner-level players that these tells will be consciously over-acted and exaggerated. If you’re playing with somewhat-experienced competition, you should train yourself to be looking for more subtle tells than the ones exhibited by beginners.
There are factors that will affect how tells are displayed and how much meaning you should assign to them. Here’s a rundown of some of the major factors:
No-limit games: No-limit games produce more stressful situations than limit games do. The most useful tells at no-limit will be related to anxiety and the release of anxiety (relaxation). The most significant tells will be more likely to be observed when big bets are made. On the other hand, no- limit players will be more likely to be harder to read than limit players at comparable stakes. You won’t see as many tells as you see in a limit game, but the reliable tells you do see will be much more profitable.
Limit games: There are not many emotion-based tells in limit, because the bets are much smaller. Tells in a limit game will mostly come from lazy players who give away their honest intentions or “tricky” players who give away information with simple attempts at deception. Many limit players, even some decent ones, don’t worry about concealing their own tells because the cost of leaked information isn’t very high and because there aren’t many observant players in most games. One important point about limit: the pot is usually offering a very good price, so you should hardly ever be making a fold based on a read, unless that read is very reliable.
Pot size: Typically, the larger the pot is, the more emotional-type tells there will be. This means you shouldn’t waste a lot of mental energy trying to study how players act in small pots. It’s still possible to see some of the more passive, lazy tells, but the most valuable information will come when you get to study how people act when they’re in the more stressful situations.
Player skill: Tells are usually the easiest to spot and use when they come from mediocre players. Good players can still have tells, but they won’t be as easy to spot. Good players are also capable of manipulating your perception of them and giving false tells (although this is pretty rare.) Your time will generally be better spent focusing on the patterns of your worst opponents. (One thing to note: if a player is completely brand-new to the game, to where they barely know how to play, it will be very hard to get accurate reads on them. Beginning players will not know the relative strength of their own hands, so interpreting their own estimation of their hand strength will not give you much information. An opponent has to be at a certain base level of competency in order for it to be possible for them to be reliably read.)
Emotion: A change in a player’s emotions can change his natural tendencies. For example, a player who normally places his chips in the pot consistently may go on tilt and start throwing his chips forcefully into the pot in certain situations, or if he’s up against a player he dislikes. Some players will become easier to read; some players will become very unpredictable and become harder to read.
The round of betting: As discussed earlier, the more well-defined a player’s hand strength is in a certain situation (like when a player bets big on the river, or pushes all-in pre-flop) the more likely the chance of getting a reliable read. The more chances of draws there are, like on the flop and turn, the more a person with a strong draw, or a vulnerable made hand, will have skewed ideas about their hand strength, and the less likely it is you will get a reliable read.