There are times when you get raised on the river and ask yourself, “What the hell could this guy possibly have? His line makes no sense.”
When a tough player, an erratic player, or an aggressive player makes a raise in a spot where there are very few legitimate hands that he could hold, you should usually call down with your bluff catchers. If it’s hard for them to have a strong hand, they don’t need to bluff that often for you to have a profitable calldown.
Take the following example:
You raise with pocket aces from the hijack. You get called by the big blind. The flop comes out K♠7♦4♦. He checks and calls your bet. The turn is another 4 from the deck and another check/call from the big blind. The river is an offsuit deuce. You bet, expecting that you always have the best hand, and that your opponent will pay you off with a king. Instead, he check/raises all in.
What could he possibly have? Why would he slowplay a set here? How could he have a 4? Why would he call the flop and turn with pocket twos? It’s so unlikely for your opponent to have anything worth check/raising all in for value. Slowplaying flopped sets or turned trips makes no sense, especially with all the draws on board. Pocket twos would usually fold before the river, and even if they didn’t, that’s only 3 combinations.
Against a player with any level of trickiness, you should call down. But what about when you’re up against a typical rakeback pro. The sort of player who’s grinding 16 to 24 tables all day long, playing a rote strategy and piling up the VPPs on PokerStars. As unlikely as it is for him to hold a strong hand, it’s even less likely for him to hold a bluff. That move isn’t in his playbook. It doesn’t matter how unlikely your opponent is to have you beat if he’s simply not capable of bluffing like this.
Against a tight, straightforward player, you’re just giving money away by calling that river. If you do call, you’re always going to look at the nuts. Why pay for the privilege? You already know what he has. Don’t put 100% of your money in the pot with 0% equity. It’s as bad as folding the nuts against a shove.
The most useful note you can have on a player is that he’s capable of doing something that you wouldn’t expect from him. Anyone can make a move on the flop. For some players, this will just be a c-bet. Others can raise with air. The population of players who can raise the turn with air is thinner still. And the population of players who can run a complex multi-street float, shove-the-river bluff, well, it’s as thin as the Rocky Mountain air. Ever seen someone hit a baseball in Colorado?