Outs discipline · Hand Lab
What does an open-ended straight draw really own?
Compare the familiar eight-out shortcut with every legal two-card runout.
01
Fixed setup
How far is the shortcut from exact showdown equity against an overpair?
Hero cards
Opponent cards
Current board
Exact result
36.87%
Hero showdown equity
- Wins
- 730
- 36.87%
- Ties
- 0
- 0%
- Losses
- 1250
- 63.13%
1,980 legal ordered runouts were enumerated; ties contribute half the pot to each player's equity.
02
Hero final-hand distribution
03
Next-card sensitivity
Each row fixes the next card, then enumerates every remaining river. Values explain board changes; they are not betting advice.
Strongest
Weakest
04
How to interpret the result
Hit probability and showdown equity answer different questions. Pairing, running trips, and opponent redraws belong in equity but not in a simple draw-hit estimate.
A five or ten completes the straight immediately, but the hero can also win through paired runouts. Conversely, completing a visible route does not prevent later redraws.
The exact result provides a benchmark for learning when the rule-of-four-and-two is a useful approximation and when it is not enough.
Calculation boundary
This study fixes both known hands. It does not infer ranges, fold equity, bet sizes, position, or future action. The program removes known cards from a standard 52-card deck, enumerates every legal community-card runout, and compares final five-card hands with the practice-table evaluator. Build tests recalculate the source data.