Hey guys,
long time no post. Was thinking about this today and thought I'd post about it.
When people think of bet sizing most of the time they will think of two factors.
1. What bet size will control the size of the pot? (i.e. i should bet less or check to keep the pot under control. I should bet more to commit myself, etc.)
2. What bet size will keep my opponent in/out? (I bet harder to get him to fold or bet less to keep my opponents weak hand in)

There is at least one other that you may confess you rarely ever think of.
3. What bet size will make my opponent the easiest to read?
I wanted to comment on this one as it is actually very important yet very few players actually pay attention to it. When we make a bet size we want to make it in a way that it will force or manipulate our opponents into being easy to read. This is what I call informational bet sizing. Let me explain with an example, and where it comes up with me the most.

Here my opponent is a Taggy reg.

PokerStars GAME #10039960640: HOLD'EM NO LIMIT ($0.50/$1.00) - 2007/05/21 - 21:34:37 (ET)
Table 'Izar II' 6-max Seat #4 is the button
Seat 1: MastrOfPuptz ($101.50 in chips)
Seat 2: Used2beGOOD ($129.80 in chips)
Seat 3: gamblegoddes ($124.55 in chips)
Seat 4: redgrape ($98.90 in chips)
Seat 6: elcheapo23 ($173.50 in chips)
elcheapo23: posts small blind $0.50
MastrOfPuptz: posts big blind $1
*** HOLE CARDS ***
Dealt to redgrape [4c 5h]
Used2beGOOD: folds
gamblegoddes: raises $3 to $4
redgrape: calls $4 (I could float this guy very easy so this call is pretty standard for me)
elcheapo23: folds
MastrOfPuptz: folds
*** FLOP *** [6s 2c 8d]
gamblegoddes: bets $5
redgrape: raises ??????

For me, it's no question i raise here. His bet was weak, which on this board seems pretty weak (although i cant be sure). If i just call here i let him have a chance to hit his overs.
The problem is is this board is low, and a lot of players are going to shove over my raise with 8x or an overpair, even a set. So what should i raise to? Here are the factors i considered.
1. If i raise to 15, he could call here with a lot of hands and possibly fold to a turn bet, while with sets he could call here and raise all in on the turn. So on the turn ill have a tough decision whether to fire a second barrel.
2. I want to convince him not to shove the flop over me with any hand.
3. So I'll raise to 22. Most of the time if he calls here he's taking it all the way so i can safely check behind the turn and take a free card. He'll thin vbet the river and ill shove if i hit.




redgrape: raises $17 to $22
gamblegoddes: calls $17
*** TURN *** [6s 2c 8d] [4d]
gamblegoddes: checks
redgrape: checks
*** RIVER *** [6s 2c 8d 4d] [5d]
gamblegoddes: bets $21
redgrape: calls $21 (obviously i cant shove because the only thing he's calling me with is beating me).
*** SHOW DOWN ***
gamblegoddes: shows [Tc Ts] (a pair of Tens)
redgrape: shows [4c 5h] (two pair, Fives and Fours)
redgrape collected $93.50 from pot
*** SUMMARY ***
Total pot $95.50 | Rake $2
Board [6s 2c 8d 4d 5d]
Seat 1: MastrOfPuptz (big blind) folded before Flop
Seat 2: Used2beGOOD folded before Flop (didn't bet)
Seat 3: gamblegoddes showed [Tc Ts] and lost with a pair of Tens
Seat 4: redgrape (button) showed [4c 5h] and won ($93.50) with two pair, Fives and Fours
Seat 6: elcheapo23 (small blind) folded before Flop

Another situation is the opposite, while i cant find the HH I'll explain it.
You have an overpair, you raised preflop UTG and got a tight caller in the BB. You know he only calls in the blinds with low pp. Your flop bet should be small. If you make a big bet it may convince your opponent to play his hands the same. in this situation he could call with both a made set and a low pocket pair, which would cause a bunch of confusion. You WANT your opponent to play as straight forward as possible, by making a big bet you made him a huge favor of balancing his range. You aren't worried about drawing out since he at most has two outs.

Big Note: You should rarely be bet sizing to manipulate on drawy boards. A lot of low stakes opponents are hard to manipulate so it's much better to make bets to chase out/keep in draws.