Short answer
The PokerDataOS leak detector reads the stats calculated from your hand histories, compares them with reference targets where they exist for your format (MTT, cash or Spins) and ranks deviations by evidence, trend and recurrence. When the sample is too small, it says so instead of flagging a leak.
What is a leak in poker?
A leak is a repeated pattern that costs you value. It is not one bad hand or a session with negative variance: it is a tendency that keeps showing up in the same kind of spot. Opening too many hands from early position, folding too often to 3-bets or calling too many rivers without enough value are classic examples.
The catch is that a leak is almost never visible hand by hand. It appears when you group hundreds or thousands of similar decisions and compare how often you take each one. That is what poker stats are for.
Which stats does PokerDataOS calculate?
The stats engine calculates the metrics MTT, cash and Spins players rely on, always from the hands you imported:
| Stat | What it measures | What it can point to |
|---|---|---|
| VPIP and PFR | Hands where you voluntarily put chips in and hands where you raise preflop | Playing too loose or too passively |
| RFI by position | How often you open-raise when nobody entered before you | Opens that are too wide from early position or too tight on the button |
| 3-bet and fold to 3-bet | How often you re-raise and how often you give up your open when re-raised | Getting exploited by 3-bets or not defending your opens |
| Blind steal and defense | How you attack and defend the blinds | Giving the blinds away or defending without a plan |
| Flop and turn c-bet | How often you keep betting after raising preflop | Autopilot bets or giving up too many pots |
| WTSD and W$SD | How often you reach showdown and how often you win when you do | Calling down too light or folding too early |
No stat works on its own. A high VPIP is not a leak if your PFR keeps pace and your format calls for it, so the leak detector reads every stat with its sample and next to the others. For a deep dive into the three most-used preflop stats, read the VPIP, PFR and 3-bet guide.
How does the leak detector decide what to review first?
A list of 40 deviations is not a study plan. The leak detector ranks them with three criteria so you start with what matters most:
- Evidence: how many opportunities support the deviation and how far it sits from the reference target. With few opportunities, a deviation may just be noise.
- Trend: whether the deviation is getting worse, getting better or holding steady compared with the previous period.
- Recurrence: whether the same deviation shows up across several periods. A pattern that keeps coming back deserves more attention than a one-off spike.
Reference targets apply where they exist for your format. When a spot has no reference, PokerDataOS shows your stat without inventing a target.
What do WEEK, MONTH and 10K mean?
They are the three comparison windows for your stats. WEEK compares the current ISO week with the previous one; MONTH compares the calendar month with the previous one; 10K compares your last 10K hands with the 10K before them, when the sample allows it. The first two show whether a recent change is visible; the third confirms with volume whether the improvement holds.
The Overall view summarizes your global picture and comes from the same stats engine, so it always matches the detailed numbers.
What happens when the sample is too small?
Every stat is a proportion, and every proportion carries a margin of error that depends on how many opportunities you had. With 50 3-bet opportunities, 6% and 12% can describe the same player. That is why the leak detector shows an explicit warning when the sample is short and never turns weak data into a leak. Waiting for more hands beats studying a problem that is not there.
How to use the leak detector in your study routine
- Import your hand histories. The more hands from your format, the more reliable the reading.
- Open your priorities. Start with the first deviation on the list, not the one that catches your eye.
- Check the sample. Look at the opportunities behind the percentage.
- Go down to the hands. Open examples of the spot in the hand replayer to see which decision drives the deviation.
- Drill the spot. Practice the decision in the preflop trainer when the leak is preflop.
- Measure across WEEK, MONTH and 10K. Confirm the change holds before moving to the next leak.
Frequently asked questions
Do I need a HUD to use the leak detector?
No. PokerDataOS does not display a HUD over your tables and offers no real-time assistance. It analyzes the hand histories you upload after playing, so you study away from the table.
Does the leak detector tell me how to play each hand?
No. It flags deviations from reference targets and ranks them by priority. The right decision in each spot is studied by reviewing the hands and practicing in the trainer.
Does it work for MTT, cash and Spins?
Yes. Stats are calculated for all three formats, and reference targets apply where they exist for each one. When a spot has no reference, your stat is shown without an invented target.
How many hands do I need?
It depends on the stat. Frequent preflop stats stabilize faster than river stats or rare spots. The leak detector warns you when the sample behind a stat is not enough.