A leak is a mistake you repeat systematically that costs you money in the long run: folding too much to c-bets, calling 3-bets out of position with dominated hands, opening too much from UTG… A single one can eat a good part of your winrate, and worst of all, you almost never see it from inside the game.
This guide explains how to find them with your own hands, without a solver and without paying for a tracker.
1. Gather a big enough sample of hands
It all starts with your hand histories: the text files where your poker site records every hand you play. If you don't know where they are, see the guide how to analyze your hand history.
The more hands the better, but you don't need 100,000 to get started: the preflop stats (VPIP, PFR, 3-bet) already give you clues with a few hundred opportunities. What you do need is to know when a number is reliable, and that has its own guide: how many hands you need to trust your stats.
2. Start with preflop
Preflop mistakes are the easiest to spot and to fix, and they repeat in every hand. Check, in this order:
- VPIP and PFR: do you play too many hands? Do you get in by calling instead of raising? A big gap between the two is one of the most expensive leaks in low-stakes cash games.
- Opens by position: compare what you open from each seat with a reference range. Opening the same range from UTG as from the button is a classic mistake.
- Open-limp: entering first with a limp almost always loses money.
- 3-bet and fold to 3-bet: if you rarely re-raise, opponents open without fear; if you almost always fold to a 3-bet, they steal from you.
- Big blind defense: the big blind always loses money; the key is to lose as little as possible.
3. Then, postflop
With your preflop in order, move on to your decisions after the flop:
- C-bet: do you continuation bet too little, or on every board?
- Fold to c-bet: if you fold a lot, your opponent wins by betting any two cards.
- WTSD and W$SD: reaching showdown a lot and winning little there means you call too much on the river.
- Aggression factor: do you take the initiative, or just call?
4. Separate real leaks from variance
Measuring a 31% VPIP doesn't mean it is 31%: with few hands, the real number can be quite a bit higher or lower. Before changing your game, check that the deviation holds once you account for the margin of error. If the whole confidence interval falls outside the healthy range, the leak is real; if it touches it, for now it's just a trend.
And don't chase your winrate: over 10,000 hands its margin of error is around ±17 bb/100. Your decision stats tell you what you're doing wrong much sooner.
5. Review the hands that cost you the most
The numbers tell you where to look; the hands tell you why. Sort your hands by how much you lost and replay them street by street: patterns almost always show up (the same line with the same kind of hand, in the same position).
Do it in two minutes with Flopmortem
Flopmortem does all of the above for you, for free: you upload your hand histories (from PokerStars, Winamax, 888poker, iPoker or ACR) and it shows you your stats by position, compared with references for 6-max and full ring, with their confidence interval so you know which leaks are confirmed and which are still trends. Then you can replay your worst hands and ask the coach why you lost them.