The Preflop tab

Welcome to the first tab of the Leak Finder, the Preflop tab. As its name suggests, it's the place where you can easily visualize your preflop ranges (and your opponents') on a 13×13 grid.

If you have the Preflop Pack, you can also compare your ranges in one click to our charts or to your custom charts, to spot any deviations.

And all of that at any stack size, in every common position, separating play vs Reg from play vs Fish .

When you land on the tab, you arrive by default on the BTN 20 bb+ situation. At a glance, you see your BTN 20 bb+ range: each cell of the grid shows how you played the matching hand, with one color per action.

Below the grid, you see the frequency of every action you took in this situation: Raise, Call, Fold, and so on.

Click an action to isolate that single action on the grid (for example, showing only the hands you raised). Each raise sizing also gets its own pill in the legend, and the + Sizing button at the end of the row lets you add one.

One last handy detail: at the bottom right of the grid, the Export chart button copies the displayed chart to the clipboard (one row per action and sizing), handy for pasting it into another tool.

One of the strengths of this tab is seeing where you deviate from a reference strategy.

Careful, the comparison made here isn't the one from the preflop mistake detector seen in the previous module.

The detector asks a binary question:

If it was, no mistake, whatever its frequency. The Preflop tab asks this question instead:

Raising a hand every single time, when the reference only raises it half the time, never counts as a mistake for the detector. Here, the gap shows.

This use is especially valuable for players who are still learning their charts: seeing your gaps to the target, hand by hand, is one of the most direct ways to spot the charts where you make the most mistakes.

The reference used depends on the vs filter in the sidebar: vs Reg compares against your GTO chart, vs Fish against your Exploit chart, and vs All against a merge of the two. We'll come back to this filter in the next section.

The comparison tools themselves live in the sidebar.

While you hover the Reference chart button, the grid displays the reference chart in place of yours.

By hovering then releasing, you compare at a glance where your range and the reference differ.

To spot the gaps without playing spot-the-difference, turn on the Show mistakes toggle: it flags with an icon the hands where fewer than 60% of combos match the reference chart.

Example

The reference plays a hand 50% raise / 50% call. You play it 10% raise / 90% fold: only 10% of your combos overlap the reference (the raise share), the 90% of fold appears nowhere in it. The error reaches 90%: the hand is flagged in red (error > 70%).

Still at the bottom of the sidebar, two scores sum up the gap across the whole range:

• Hands: the percentage of hands you played with the action the reference expects. An all-or-nothing read, hand by hand.
• Frequency score: how close your frequencies are to the reference's. The smaller the gap, the higher the score.

The outline of each score is colored according to its quality (green, yellow, orange, red).

As we saw in the chapter on preflop mistakes, don't try to reach 100% on the Hands score: some deviations are relevant, even necessary, in game. Aim instead for around 85% on that score, a level that shows your strategy stays broadly close to the reference without erasing the adjustments the context justifies.

Still in the sidebar, you can narrow down the situation to analyze: table format ( 3-max or HU), position, and which opponent you're up against, via the vs filter.

This filter offers vs All (the default), vs Fish, vs Reg, but also any of your custom tags or even a specific player. The grid recomputes to show only the hands you played in that exact context.

This Fish/Reg classification logic works the same way in all four tabs of the Leak Finder. Once you've got it here, it carries over as-is to Postflop, Global EV and Overview.

A range displayed on too few hands can be misleading, and above all incomplete: most combos haven't been played yet, and the handful of visible hands isn't enough to describe your real strategy.

The threshold isn't magic. On a very binary situation (all-in/fold play at 12 bb), 500 hands are plenty. On a mixed situation with four possible actions, it's only a comfortable minimum.

And as you probably guessed, the number at the bottom right of each cell shows the number of occurrences for that hand.

• Your pool's reg/fish ratio stabilizes after very few spins: variance is low, since each opponent is classified in a binary way (either Reg or Fish).
• A preflop range (yours or the pool's) needs a moderate sample per situation, that's the 500-hand threshold we're talking about here.
• CEV needs far more spins to converge: the variance of EV per tournament is high, and it typically takes several thousand spins before it becomes reliable.
• An EV per situation needs even more volume: the data is split into finer subgroups, so each category gets less signal for the same number of spins.

There are a lot of stack sizes and a lot of situations. Going through them all to find every one of your leaks is hard. Two concrete approaches to get there.

It shows all your preflop situations in a single table, fed live by your filters. A Total row at the top, then for each situation:

• the number of Hands played;
• your Accuracy and your number of Mistakes, broken down vs Fish and vs Reg .

The headers are sortable: sort by accuracy to bring your worst situations to the top, or by hand volume to push aside statistical noise.

Accuracy is measured against your reference charts: the Poker Sciences charts by default, or your custom charts (see the next chapter).

By default, every stack depth is aggregated, but the stack ranges card in the sidebar lets you restrict the table to certain depths.

And to dig into a situation, click its row: the tab switches straight to that situation, pre-selected, where you can analyze stack by stack where the mistakes come from.

So far we've talked about your range. But the Preflop tab also shows, on the same situation, what the Fish or the Regs do.

The profile bar, at the top of the sidebar, lets you tick up to three profiles at once: Hero, Fish, Reg, any of your tags, or even a specific player. Each ticked profile displays its own grid, side by side with the others.

To read these ranges properly, compare both the action frequencies and the composition of the grids. Here, for instance, is the same BB vs BTN open 2x situation at 20 bb+, on the Hero side, the Regs side and the Fish side:

In this particular example, the frequencies already tell you what matters: Fish defend the BB in a much looser way.

But it's by looking at the composition that the read becomes usable: which hands they min 3-bet, which extra hands they call, which hands stay folded.

With these opponent ranges in front of you, let's get back to the essentials. Two very concrete uses come out of this read of the pool:

Seeing how they really play

We often carry assumptions about Fish that turn out to be wrong (or not) as soon as we look at the data:

It teaches you a lot, independently of any exploit strategy. If you sometimes wonder how the Fish (or the Regs) play a specific situation, this is where you come to check.

Building exploit preflop strategies

From the range the pool actually plays, you can do what's called nodelocking: you force that range onto a solver, and ask it to compute the best possible response. The output is a strategy that directly exploits the pool's gaps.

The Preflop tab is the tracker's tool for visualizing and comparing preflop ranges. It works both ways: your game on one side, the pool's game (Fish and Reg) on the other.