A scare card weakens your perceived range while it strengthens your opponent’s perceived range. An overcard such as an Ace or a king is usually used in pots as a scare card. Here is a simple example.
Usually in this situation, if I don’t have a hand with showdown value, I will raise the turn. This is because Villain would bet at the turn Ace almost always. However, the strongest hand in his range is AK, and even that is a little optimistic since he usually bets the flop with that hand. He can’t have two pair because he would’ve bet the flop with A3, A8, and A9. He might show up with a set, but that rarely happens because players almost always c-bet to build the pot when they flop a set. So, his turn range is usually an Ace with a weak kicker or some random hand. How do we counter his bet? As always, the answer depends on the type of opponent you are dealing with.
If I’m facing a fishy player, then I will make a 3x raise on the turn and give up if he calls. Fishy players don’t like to fold Ax. When I’m raising the turn, it’s to fold all his random hands. One can make an argument for calling the turn and betting the river if it is checked to you. However, what if the fishy player doesn’t check to you on the river and bets again? He may be value-betting with an ace or bluffing. We don’t know. For this reason, I like to make a turn raise and give up.
If I’m playing against a regular player, then I will raise this turn almost always and follow through with a river bet. A decent player will realize that my range contains a lot of strong hands. It’s normal for anyone to check back the flop with a set, A9s, A8s, and A3s. If you bluff the river and get called, then take a note that he likes to call with a marginal hand when he realizes it’s the top of his range. Either that or he doesn’t like folding top pair. What usually happens is that the table regular folds to the turn raise or calls and folds to a big river bet. You must remember to follow through with your river bet. If you don’t intend to bet the river, then it’s best to fold to his turn bet and save yourself some money.
Regarding the above situation, I will give up on the hand if the board pairs. All your value hands are less likely now and players will have trouble folding a pair of aces on a paired board.
Let’s look at a more complex example.
Before getting to our decision, let’s analyze the hand, street by street. Pre-flop is normal. On the flop, there are a lot of high-card hands and semi-bluffs that Villain can have in his range so we call. The turn is an interesting card because he can easily have a pair of kings (AK, KQ, KTs). He can also have sets, two pairs (KJ), one pair such as QJs, AJ or AA. However, he will also have a lot of flush draws and straight draws (T9s, QTs, ATs, AQ). Combination-wise, that’s 12 combos of AK, 12 combos of KQ, 3 combos of KTs, 12 combos of sets, 9 combos of KJ, 3 combos of QJs, 12 combos of AJ and 6 combos of AA. That’s 66 combos of value hands that he’s betting on the turn.
For semi-bluffing hands, he has 2 combos of T9s, 4 combos of QTs, 4 combos of ATs, 16 combos of AQ, 4 combos of 76s, 2 combos of 79s and about 10 combos of Ax of spades. That’s roughly 42 combos of semi-bluffing hands, plus a few random hands that he may bluff the turn with since it’s such a great card for his range and such a bad card for our range. Let’s give him ten of these random hands. We beat about 52 of Villain’s hands on the turn, so we should fold the turn. But since we made a bad turn call, we get to the river.
The river is an interesting card because it polarizes his betting range. You have a few Jx in your range that he has to be afraid of. This means that he’s going to shove the river for value with hands such as QJs (2 combos), AJ (8 combos), 55 (3 combos), 88 (3 combos), KK (3 combos), JJ (one combo). That’s a total of 20 hands on the river. Sometimes he will value-shove with hands such as AK and AA, but he is more likely to check-call with those holdings, so the times they bet will negate the times they check, so we don’t have to account for them in our calculation. What about his drawing hands?
Now let’s assume that he gets to the river with the 52 hands that we assigned him on the turn. If he bluffs with half of them, it is an easy call because we will win half of the time while getting 2-to-1 odds. But since micro- and small-stakes players don’t bluff that often in this spot, we have to adjust Villain’s bluffing frequency. In reality, bluffing frequency in this spot is about 20 to 25 percent in low-stakes games. Nevertheless, if Villain is an aggressive opponent who follows through with his bluff sometimes, you should call. If Villain is a nit, fold. A nit will show up with the rare nut hands in this spot all the time.
What is the main reason for showing you this hand? It is to show you the hand analysis that I go through away from the table to improve my game. It is also to show you that when a turn scare card comes, it increases Villain’s bluffing frequency dramatically. More importantly, it is to show you that if an opponent represents a strong hand on the turn but the river improves your perceived range and narrows his value-betting range a lot, you should call a big river bet. Unless, of course, you are dealing with a 9+ tabling nit who will check the river if he doesn’t have trips or better because he is afraid you have Jx.