转牌子集（Turn Subset）
Turn Subset
In Texas Hold'em, based on the turn card dealt, a specific set of combinations filtered from a player's initial hand range that are relevant to the current board.
Concept
The turn subset is a key concept in range construction. Players have an estimated opponent hand range on the flop. After the turn card is dealt, not all flop range combinations remain possible. Only those combinations that are coordinated with (i.e., do not contradict) the turn community cards constitute the turn subset.
Application Logic
- Exclude Uncoordinated Combinations: For example, the flop is K♠9♣2♥. The player's flop range includes top pair, middle pair, straight draws, etc. The turn is Q♦. Then the originally possible 9x middle pair still exists, but the originally possible QJ straight draw now becomes top pair, and the originally possible Q9 two pair becomes possible. At the same time, some combinations like 72 (bottom pair) may be excluded because the turn has weak connection with the board.
- Retain and Add Combinations: The turn subset retains all combinations that do not conflict with the turn (including combinations whose hand strength hasn't changed), and may add some combinations that were not in the flop range but become reasonable draws or made hands after the turn (e.g., the turn hits a backdoor draw).
- Used for Decision-Making: By analyzing the opponent's turn subset, players determine their likely value hands, draws, or bluff combinations, thereby deciding actions such as betting, raising, folding, etc.
Relationship with Flop Subset
The flop subset is the range subset on the flop, while the turn subset is the result of further filtering on that basis. As community cards increase, the player's range gradually narrows, and the subset becomes more specific.
Example
Assume the flop is A♠Q♠9♦, and the turn is J♠. A tight-aggressive player's flop range might include: AK, AQ, KQ, QJ, QT, T9, TT, JJ, AJ, AT (and flush draws like K♠X♠, T♠X♠, etc.). After the turn J♠ appears, the turn subset includes:
- Made hands: AJ (top pair with straight draw), QJ (middle pair with straight draw), JJ (three of a kind), AQ (top two pair), AK (top pair), etc.;
- Draws: K♠T♠ (flush draw+straight draw), T♠9♠ (flush draw+pair), K♠X♠ (flush draw only), etc.;
- Excluded: originally possible 99 (three of a kind, but not excluded by the turn), TT (middle pair, but still exists since no J hit), etc. are retained, but completely unrelated combinations like 72 are excluded.
Strategic Significance
Precisely calculating the turn subset helps players quantify the probability of an opponent's strong hands, thereby formulating better raise frequencies and hand range counter-strategies.