Expectation
Expectation is the amount you expect to win or lose on average from a certain play.
The simple explanation
Expectation measures the average result of a decision if you made it many times. Suppose you pay $10 into a $50 pot to draw at a hand that makes 25 percent of the time and always wins. You lose $10 three times and win $50 once. Over four hands, you gain $20, so your expectation is $5 per hand.
A closer look
Expectation is the same idea as expected value. A play with positive expectation is profitable in the long run even though individual hands may lose. The word is also used for earnings over time: winning $527 in 100 hours of play is an expectation of $5.27 per hour. Good players compare the expectation of different options, such as calling, raising and folding, and choose the highest.
A practical example
Calling $10 to draw to a hand that wins $50 one time in four has an expectation of +$5 per call.
Full explanation
Expectation is the amount you expect to win or lose on average from a certain play.
Expectation is the average amount you expect to gain on a certain play. If a play has positive expectation, it earns money over many repetitions.
The calculation weighs the chance of each result by the amount won or lost. In the example, a draw that costs $10 and wins a $50 pot 25 percent of the time gains an average $5.
It is another name for expected value, which poker players write EV.
The result of a single hand can differ from the expectation. The figure describes the long run.
The value of a call under stated assumptions
No-limit Hold’em · Blinds 1/2 chips · No rake
A has seven winning rivers out of 44. For this worked decision, assume no more betting after a call and no rake.
Read the example transcript
Player A has the button (BTN) and posts the 1-chip small blind (SB). Player B posts the 2-chip big blind (BB).
- Turn · Pot: 12 chips
A has seven winning rivers out of 44. For this worked decision, assume no more betting after a call and no rake.
Board: QQueen of hearts (Qh)88 of hearts (8h)22 of clubs (2c)33 of diamonds (3d)
- Player A BTN / SB AAce of hearts (Ah)KKing of hearts (Kh) · Stack 194 · In this round 0
- Player B BB QQueen of clubs (Qc)QQueen of diamonds (Qd) · Stack 194 · In this round 0
- Turn · Pot: 14 chips
B bets 2 into 12. A must add 2 to contest a final pot of 16.
Board: QQueen of hearts (Qh)88 of hearts (8h)22 of clubs (2c)33 of diamonds (3d)
- Player A BTN / SB AAce of hearts (Ah)KKing of hearts (Kh) · Stack 194 · In this round 0
- Player B BB QQueen of clubs (Qc)QQueen of diamonds (Qd) · Stack 192 · In this round 2
- Turn · Pot: 16 chips
A calls 2. The expected value of this call, compared with folding, is (7/44 × 16) − 2, about +0.55 chips. It is the average over possible rivers, not a promise to win this hand.
Board: QQueen of hearts (Qh)88 of hearts (8h)22 of clubs (2c)33 of diamonds (3d)
- Player A BTN / SB AAce of hearts (Ah)KKing of hearts (Kh) · Stack 192 · In this round 2
- Player B BB QQueen of clubs (Qc)QQueen of diamonds (Qd) · Stack 192 · In this round 2
Cards are shown for learning; totals are displayed before pot collection.