River Call Range Construction Guide

Position Scenario Description

The scenario discussed in this article is: 6-max cash game, 100bb effective stacks. Hero enters the flop after either raising or calling preflop, then after betting and calling on the flop and turn, faces a raise on the river (not all-in, raise size around 2-3x pot). Assume Hero holds a certain range, and the opponent uses the river raise to represent a polarized range (strong hands or bluffs).

Recommended Range (Text Description)

When facing a river raise, Hero's calling range should include three types of hands:

1. Strong hands top pair and above: including top pair top kicker, two pair, trips, straights, flushes, etc. These hands have enough strength to beat the opponent's value raise range.
2. Bluff catchers with blockers: such as holding A-high and blocking the opponent's nut flush or straight, or holding medium pairs when the board has high cards. These hands profitably call by blocking the opponent's most likely value combos.
3. Specific missed draws with showdown value: e.g., missed flush draw on the flop but holding middle pair or bottom pair with no improvement, can also consider calling if the opponent might be over-bluffing.

The specific range depends on the board. A typical example: on a J♠8♥4♣2♦3♠ river, Hero's calling range could include: AJ+, KJ, QJ, JT, 99-77, A8s, K8s, missed flush draw Ax (e.g., A♠X♠).

Range Construction Logic

1. Value vs. bluff balance: The opponent's river raise range is usually polarized: value combos (e.g., made hands stronger than most of your range) and bluff combos (e.g., missed draws). Hero's calling range needs to cover the bottom of the opponent's value range and beat their bluffs.
2. Minimum Defense Frequency (MDF): Calculate the required calling frequency based on pot odds. For example, if the opponent raises to 2x pot, Hero needs to call 1x pot, odds 2:1, MDF=1/(1+2)=33.3%. That is, Hero should call about 33% of their river betting range.
3. Exploitative adjustments: If the opponent under-bluffs, narrow the calling range; if the opponent over-bluffs, widen the calling range.

Adjustment Factors

1. Opponent type: Against tight weak opponents, narrow the calling range; against loose aggressive ones, increase calls.
2. Board texture: On dry boards, opponent's value raise is more credible, reduce calls; on wet boards, bluff potential is higher, increase calls.
3. History dynamics: If Hero has previously folded in such board situations, opponent may become more aggressive, requiring adjustment in calling frequency.
4. Position: When Hero is in position, the calling range can be slightly wider because later action can be evaluated; out of position, it needs to be stricter.

GTO Reference

From a GTO perspective, the river calling range should have the following characteristics:

• Include all hands top pair top kicker and above.
• Include some medium pairs as bluff catchers, proportion depending on the board.
• Exclude pure air (e.g., high cards with no showdown value).
• Fluctuate around MDF, but not mechanically applied; Nash equilibrium must be considered.

A simple reference: when the opponent's river raise is 50% pot, MDF is 2/3, Hero should call about 2/3 of their river range; when the raise is 2x pot, MDF is 1/3.

Practical Application

Case 1: Hero holds K♠Q♣, board A♦9♥5♠2♦3♣. River opponent bets pot and then raises to 2x pot. Hero's KQ hits K-high, but top pair A exists and opponent likely holds A or a bluff. Since Hero's KQ blocks opponent's KJ, KT, etc., and has no showdown value, Hero should fold.

Case 2: Hero holds A♥J♥, board K♥Q♦7♣3♠4♥. River opponent bets pot and then raises. Hero has A-high, blocking opponent's AK, AA, while top pair K exists. Since the board has flush possibilities, Hero's A♥ is a good bluff catcher and can consider calling.

Summary: When facing a river raise, construct a reasonable calling range based on board texture, opponent tendencies, and pot odds. The core is to defend against over-aggressive bluffs and exploit opponent's mistakes of value-raising too wide.