Most opponents who think or delay longer than is normal and then check are trying to imply that they have a better hand than they actually have. They are trying to indicate strength by thinking about betting, but they really want you to check so that they can get a free hand. If your opponent was going to check-raise he would generally check at normal speed and then raise.

The reverse of the above is true, in that an opponent who "thinks" a long time and then bets usually has a strong hand. He is trying to lure you into calling by thinking a long time before betting.

Most players who bet or raise instantaneously using automatic buttons generally have strong hands. This is all about reverse psychology, your opponent thinks that you think that he would never raise so fast with a strong hand, therefore he uses reverse psychology and raises instantaneously to make you think that he is weak.

This tell has varying degrees of reliability depending on the street. On the river an instantaneous raise almost always means the nuts or a hand close to it. On the turn it generally indicates a very strong hand. An instantaneous raise preflop also generally indicates a strong hand, especially from early to middle position, however it is not so easy to make generalisations if they are in a late position and are raising a late position player, since they might just be bullying their opponent.

Many players use the check/fold button when they plan on folding their hand to any bet, this is especially true if the player is playing more than one table. There are 2 situations where you can use this information to your advantage. Lets say that you are in last position, the first player checked and the middle two checked instantaneously, since the middle players probably don’t have anything a bluff will probably be successful against the lone opponent who checked early. Another situation occurs when you are the player who checks early, if your opponents instantaneously check behind you, you could have a bluffing opportunity on the next card. Many players play 2 games at once and use these buttons to quickly move back and forth between hands.

As stated above a quick check often indicates weakness, however if the player checks quickly and then raises, be very careful!! When a player check-raises, the quick check was probably an attempt to indicate weakness so that you would bet into his strong hand.

Remember that all these tells are generalisations, they work best against unknown opponents, however once you have played with a player for a while observe their betting patterns and style of play and use your judgement using all the information available.