The CO is to the left of the Middle Position (MP). It is the second most profitable seat in a 6-max game, second only to the button. Playing from the CO allows you to play in position in most pots; therefore, you will want to isolate and 3-bet more often.
Here is a range of hands that you should be playing from the CO: 22+ (all pairs), broadway cards, suited and offsuit (AT, KJ, QT, JT, etc.), A9o+, A2s+, K9s+, Q9s+, medium suited connectors (J8s+, 97s+, 87s, 76s, 65s).
This makes up about 24 percent of hands. As you improve, you can add more suited two- and three-gappers such as T7s and Q8s to your range. The same principles about limping behind and 3-betting apply here, although you now only have to worry about the button behind you.
You can limp behind with even more hands from the CO (Axs and T7s). One thing worth noting is that with one limper in front of you, you should be more inclined to raise and isolate him. The problem with isolating against two limpers is that if the first limper calls, the second will likely come along as well. Unless they both play very straightforward on the flop, just limp behind.
Isolate with the same hands from MP and more. Any broadway cards are fine. So is the majority of suited hands (85s, 96s) higher than a 6. Weaker players will usually just limp- call or limp-fold and check-call or check-fold the flop. By isolating, you will have the lead on the flop, and the decision to bloat the pot or not usually rests on you. Isolating from the CO is also more profitable than from MP because you only have one player sitting behind you instead of two. This decreases the chance of you getting 3-bet lightly.
Good hands to raise with are hands that do well in heads-up pots. For example, you should isolate with KTo way more often than with a hand like 65s against a limper. Broadway hands such as KTo plays well post-flop because when you flop a pair, it is usually the best hand and has less chance of getting outdraw. The same can’t be said for low cards such as 65s or 54s.
Your range for 3-betting in this spot should be polarized to the nuts or speculative holdings such as 65s or 97s that can’t profitably call a pre-flop raise from a tight player.
If UTG or MP is a fish, then I would expand my 3-betting range since it will discourage the button from over-calling and making this a multi-way pot. This allows you to steal the initiative from the fish and play him heads-up against you while you have position. If the button or blinds are capable of 4-betting light in this spot, then I would tighten up my 3- betting range and would be more incline to get it in with TT+/AQ+. However, in the micro- and small-stakes games, 4-betting light doesn’t happen often. You usually see KK+/AK if someone 4-bets you.
Stealing the Blinds
Keep stealing from the CO with your normal pre-flop range and gradually widen the range as you improve. Although you will put yourself in marginal spots and may not feel comfortable at first, you will eventually. Once that happens, you will have a bigger edge over players in the blinds.
A simple example:
You should definitely RAISE here because you have position and this hand plays well post- flop. The only time you should consider folding this hand pre-flop is if the BTN is 3-betting you way too often.
One more example:
You should CALL here almost always. Raising is not optimal because we know that UTG likes to limp-call with a strong range. Some of my students would auto-raise to isolate in this spot without giving any thought to the UTG’s limping range. He has a strong hand so call and try to make two-pairs or better to stack him.
If you isolate the limper, there is also the possibility that the BTN and the blinds 3-betting you and forcing you to fold. If you only call and players behind you isolate, you can call and hope to flop a big hand after the fish calls.