EV Decision Lab

This tool models the expected value (EV) of betting versus checking/calling in a heads-up pot on any street (flop, turn, or river). It compares the long-term profitability of two main options:

• Betting: You put money in to deny equity, fold out better hands (fold equity), or get value from worse hands.
• Checking/Calling: You give a free card or let villain bet, then decide to call (often as a bluff-catcher) or fold.

The model assumes a simplified heads-up spot with no future streets (or treats the decision as final for EV purposes). It helps answer: "Is betting +EV here, or should I check and realize equity / catch bluffs?"

Step 1 — Enter Pot Size

The current size of the pot before your action (in big blinds, dollars, or chips — units don't matter as long as consistent).

Why it matters: Pot size is the "reward" baseline. A larger pot increases the value of folding out your opponent (more chips won immediately) and amplifies the cost of getting called (you're risking more relative to the reward).

Examples:

• Flop: You raised pre, got called → pot = ~9–12 BB
• River: Multi-street action → pot = 150 BB or more

Do not include any bet already made on this street. Enter only what's already in the middle.

Step 2 — Enter Bet Size

The amount you are risking with your bet/raise right now — the exact size you plan to put in (or are facing if you're the caller, but this tool is from the aggressor's perspective).

Why it matters: Bet size directly controls:

• How much fold equity you need (larger bets require more folds to break even)
• How much equity you need when called (larger bets demand more showdown value to be profitable)
• Your opponent's pot odds / defense frequency (bigger bets make calling worse for them)

Common sizes & intuition:

• 33–50% pot: Small / probing / thin value / multi-street bluffs
• 66–100% pot: Standard value / semi-bluffs / polarized spots
• 125–200%+ pot: Overbets — max pressure, huge fold equity needed or nuts-or-air

Enter the raw amount (e.g., 75 if pot is 100 and you're betting ¾-pot). The tool auto-calculates ratios like MDF and break-even bluff % from this.

Step 3 — Enter Fold %

Your realistic estimate of how often your opponent will fold to this exact bet size (as a percentage: 0–100).

Why it matters: This is your fold equity — the free money you win immediately when they fold. Fold equity is often the biggest driver of EV for bluffs and semi-bluffs.

How to estimate it accurately:

• Think villain's range: How many hands continue vs this size? (nuts, draws, medium pairs?)
• Board texture: Scare cards (flush draws complete, straights hit) → higher fold %
• History / player type: Tight players fold more; calling stations fold less
• Street: River fold % often lower than flop/turn

Typical ranges:

• Strong board / value-heavy spot: 20–40%
• Scary river card / polarized bet: 50–75%+
• Pure bluff on dry board vs station: 10–30%

Step 4 — Enter Equity When Called (%)

Your estimated share of the pot if villain calls and you go to showdown (0–100%). This is your raw equity vs their continuing range.

Why it matters: When they call, the hand usually goes to showdown → your equity determines how often you win the final pot (and thus whether betting was +EV even after they call).

How to estimate:

• Use equity calculators (Equilab, PIO, Flopzilla) vs villain's likely calling range
• Bluffs/semi-bluffs: Often 0–35% equity
• Thin value: 40–65%
• Strong value/nuts: 70–100%

This is not your equity if checked back — it's specifically when called (so villain's range is stronger than if they checked).

Model Output Interprets:

• Bet EV — Chips you expect to win/lose per hand if you bet (positive = profitable long-term)
• Call EV — EV if you check (and call if bet into) — simplified as realizing your equity without betting
• Dominant Action — BET, CALL (check), or INDIFFERENT — which line is clearly better
• Required Equity to Call — Minimum % you need to have to call profitably if facing this bet size (pot odds derived)
• MDF — Minimum Defense Frequency: % of hands villain must defend with to prevent you from auto-profiting with pure bluffs (pot / (pot + bet))
• Break-even Bluff % — Fold % villain needs to give you for your pure bluff to have zero EV (bet / (pot + bet))

Positive EV = profitable long term. Negative EV = losing long term. Use this tool to train your intuition — over time you'll get faster at estimating fold % and equity without calculators.

Pro tip: Try extreme values first (e.g., 80% fold + 10% equity = massive bluff EV) to see how sensitive the model is — then dial in realistic numbers.