[Magikist]

The tenor of your post makes it sound like you lost to QT or KK, but don't be results oriented. There's a large range of worse hands that CO could raise the river with: AK, KQ, KJ, KT, K9, Kxc, to name the most likely. Barring extraordinary circumstances, not 3-betting the river is a mistake.

What intrigues me about this hand is not the river, though. I think simply calling SB's lead out on the flop is a very viable alternative to raising. In the heat of multi-tabling, I would probably raise the flop, too. But after some consideration, I think this is one of those less obvious situations in today's 6-max game where a touch of subtlety will go a long way.

CO is raising here with a large range of hands. If he's aggressive enough, you can reasonably expect him to raise the flop fairly often, allowing you to 3-bet or 4-bet. If he's good enough, he will fold hand you don't necessarily want him to fold. By smooth-calling the first bet, you're not putting so much pressure on SB, either, whose lead out often means that he really just wants to fold.

Generally, this is one of the better money-making spots in 6-max poker. You stand to rake a huge pot by letting your opponents "hit" their hand. With 11 crushing outs (9 clubs and 2 aces), you can expect this scenario to play out often enough.

Yes, raising the flop will increase your odds of winning the pot. With vulnerable hands of value in multiway pots, this concern is of tantamount importance. However, here you are presented with a hand with a ton of equity in an awkward position. The appropriate strategy may need to change to: either build a big one right off the bat, or go for trapping your opponents so they pay off on bigger streets.

As in all things, the more risk the larger the reward. This spot is the genuine article that justifies the increased risk. Calling the flop here has significantly higher value than immediately raising.