Delta EV (ΔEV)

ΔEV (Delta EV) measures the absolute expected value difference between the action you took and the best possible GTO action. It shows the direct EV cost of a decision, independent of pot size.

Understanding ΔEV lets you see exactly how much value you lose when you deviate from optimal play. This is the raw dollar (or big blind) amount your mistake cost you, making it easy to identify which hands are bleeding the most EV from your game.

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How it's calculated

For every decision, the solver evaluates the EV of all available actions - bet, check, raise, call, or fold. The highest EV action is considered optimal.

ΔEV = EV(GTO Action) - EV(Your Action)

Here's what that means in practice:

• If you take the GTO action, ΔEV = 0. Perfect play, no EV lost.
• If you make a suboptimal decision, ΔEV becomes a positive number showing how much EV you lost.

For example, if the GTO action has an EV of 50bb and you chose an action with an EV of 35bb, your ΔEV is 15bb. You lost 15bb of expected value by making that choice.

What it tells you about your play

ΔEV reveals the raw cost of mistakes in EV units (big blinds or dollars):

• A high ΔEV (10bb+) indicates a major error that's costing you serious money
• A low ΔEV (<2bb) indicates a minor deviation that barely affects your results

Sorting your Handlist by GTO ΔEV helps you quickly find the most expensive mistakes. The hands with the highest ΔEV are where you strayed furthest from GTO and lost the most value.

These spots often reveal structural leaks in bet sizing, range selection, or decision logic. If you're consistently making high ΔEV mistakes in the same situation, that's a fundamental gap in your strategy.

ΔEV vs EV Loss %

ΔEV and EV Loss % both measure mistake size but from different perspectives:

ΔEV shows the absolute EV cost of a mistake. It's ideal for identifying the most expensive hands in monetary terms.

EV Loss % shows the relative cost of a mistake compared to the pot size. It's useful for detecting proportionally large leaks.

Example:

• A small mistake in a big pot → high ΔEV, low EV Loss %
• A big mistake in a small pot → low ΔEV, high EV Loss %

Both metrics matter. Use them together to understand your results completely. ΔEV tells you which hands cost you the most money. EV Loss % tells you which hands were the worst decisions relative to the situation.

Where you see ΔEV

ΔEV appears in multiple places throughout FlopHero:

In the Handlist

The GTO ΔEV column shows the total EV lost across all decisions in that hand. Sort by this column to find your most expensive hands first.

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In the GTO Replayer

The GTO Replayer shows ΔEV for each individual decision. You can see exactly which street and which action cost you the most EV.

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You can change between ΔEV and EV Loss % by clicking in the Display button on the top right corner.

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In the Session Dashboard

The Session Dashboard shows total GTO ΔEV for each session. This tells you how much EV you lost in that session due to suboptimal decisions.

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Using ΔEV to improve

Focus study time on hands with the highest ΔEV values. These are your most costly decisions over time. Here's how:

1. Sort by ΔEV. Open your Handlist and sort by the GTO ΔEV column. Start at the top.
2. Review in the Replayer. Open each high-ΔEV hand in the GTO Replayer and see exactly where you went wrong.
3. Ask the right questions. Was I overvaluing my hand strength? Did I misread opponent ranges? Was I applying the wrong strategy for stack depth or position?
4. Look for patterns. If you're making high ΔEV mistakes in the same spot repeatedly, use Reports to filter for those situations and study them systematically.
5. Track your progress. Monitor your average ΔEV per session over time. As you fix leaks, this number should decrease.

Correcting your biggest ΔEV spots first delivers the fastest skill gains. Don't waste time on 0.5bb mistakes when you're still making 20bb blunders.

Combine ΔEV review with consistent study in the GTO Replayer to convert leaks into long-term improvements. Fix the expensive mistakes first, then work your way down.