Recently I've been paying a lot more attention to timing and deciphering it's meaning. First of all, one can make a big mistake by taking it for granted: just because someone took a long time to act, doesn't mean he's weak or something - he might be busy at other tables, telephone just rang, connection problems, etc. You can only really be sure that quick action means he acted quickly. There is one more mistake, I used to be making: even if you correctly put someone on hand, say you call PFR w/ 55, flop comes 772 and you are 99.99% sure he doesn't have a 7, DON'T try to bluff him if he is bad and will stack off with overpair.

In other words knowing the player and betting patterns are far more important. This is just a little extra info.

Here are the ones I found to be relatively reliable, having in mind all above mentioned:

1) one-second-to-call = SLOWPLAYING : ex. you raise preflop OOP, got a caller, cbet and he takes a second then calls. This is really hard to define precisely, but I noticed it more than a couple of times. It is the length of his pause that is important. You get a feeling that he just took a deep breath and acted. It takes roughly about 1 second - no more, no less.

2) one-second-to-call-preflop = BIG HAND : same thing as 1) only he took the same 1 second before calling your preflop raise. This often means he has a big hand himself and was just about to raise when you did it. If you have AA and he one-second-to-calls your PFR and one-second-to-calls your cbet on a ragged flop, don't worry about slowplaying. Chances are he has a big PP and you've got him by the balls.

3) ThinkThank-Turn-MinRaise = MONSTER : you've all seen this, I'm sure. You bet, villain thinks (acts) about 2 or 3 seconds then minraises - he has a monster and is trying to extract the most without scaring you.

4) InstaCbet-into-rags = MISSED FLOP ie OVERS : I'm always suspicious when someone insta-cbets into non-ace/non-broadway flop. Often I found it to be missed flop, but BE WARNED: if the flop contains draws it is quite possible that the villain has AA and is afraid of being outdrawn so he bets quickly and is ready to go to war on flop. This one is actually not that reliable, so floating on brick turn is probably safer strategy.

5) Thinking-calling = HE'S SCARED: It's often said: "when they are thinking, they are thinking about folding". Note the difference between this and 1) one-second-to-call. In first case we had 1 second before acting and in this case we have more, usually 3 sec or more. Here's example from the hand I played: I PFR w/ AQo and got one caller (weak tight), flop: 992, I cbet 2/3 (standard) he thinks ... and calls (now I have a lots of information: he has a PP, doesn't really believe that flop helped me AND he is SCARED, that's why he took 4, 5 seconds to call), turn: 2, I fire second barrel 3/4 pot, he thinks ... thinks ... and folds. He WAS scared. It is this slightly longer pause that I rely on when deciding whether to 2nd-barrel or not.

6) I found this one in Rizen's blog:
Quote Originally Posted by Rizen
A lot of players, when they bluff river scare cards, will insta-push all in without hesitation. I've caught lots of people bluffing this way, and against a lot of players it's pretty reliable.
So did I just an hour ago . Thank you Rizen for valuable insight.

7) NOT EVERYBODY IS THE SAME. I must stress it again: knowing the player and betting patterns are of utmost importance. If you notice that particular villain takes n seconds when on a draw then adjust accordingly.

Finally, this is meant to be used against bad players. Good ones are quite capable of misguiding you into wrong conclusions.

Thoughts?
Your own insights?