HUD

A HUD is a heads-up display: software that overlays statistics about each opponent directly onto an online poker table, drawn from hand histories collected as you play. It was once standard equipment for serious online players, and it is now prohibited in a growing number of places.

Typical HUD stats are VPIP, PFR, 3-bet percentage, fold-to-c-bet and aggression frequency. HUDs let regulars exploit specific opponents at scale, which is why sites such as GGPoker prohibit third-party tracking tools and instead provide their own built-in statistics.

How one works

A tracking program imports the hand histories the poker client writes to disk and builds a database from them. The HUD reads that database and renders a small panel beside each player's seat, updating as more hands are logged.

The crucial limitation follows from the mechanism: a HUD only knows hands it has observed. It cannot see what an opponent did at a table you were not sitting at, and against a player you have just met the panel shows almost nothing.

The core statistics

A handful of numbers carry most of the information.

- **VPIP** — how often a player voluntarily puts money in pre-flop. The basic loose-or-tight measure. - **PFR** — how often they raise pre-flop. Read alongside VPIP; the gap between the two describes whether the player is aggressive or passive. - **Three-bet percentage** — how often they re-raise, which indicates how much pre-flop pressure they apply. - **Aggression frequency** and **continuation-bet percentage** — post-flop tendencies. - **Fold to continuation bet** — arguably the most directly actionable of all, since it says how often bluffing the flop will simply work. - **Won-at-showdown** figures, which suggest whether a player is reaching showdown with hands too weak or too strong.

Sample size is the whole caveat

Every one of these numbers is an estimate, and the error on it is large until the sample is substantial. Pre-flop statistics settle fastest, because a decision is recorded nearly every hand. Post-flop statistics are far slower, because the relevant situation only arises some of the time — a fold-to-continuation-bet figure drawn from a handful of opportunities is close to meaningless.

The predictable failure is treating a number from a small sample as a fact and building a large bluff on it. A disciplined user reads the sample count before the statistic.

What a HUD cannot do

It describes averages across many hands. It does not know the hand in front of you, the dynamic at the table, or that an opponent has just lost a big pot and is playing differently from their own long-run numbers. Players who substitute the panel for watching what opponents actually do become exploitable in a specific and well-known way: their decisions become predictable functions of statistics the opponent can reason about too.

The rules have changed

This is the part that matters most in practice. Many operators now prohibit HUDs and third-party tracking software outright, and several have redesigned their software to make them unworkable — anonymous tables, seating restrictions that prevent table selection, and hand histories released only for hands a player took part in.

Some jurisdictions also restrict such tools as a condition of licensing, independently of what the operator would otherwise permit.

The consequence is that there is no general answer to whether a HUD may be used. It depends entirely on the specific room and the licence it operates under, and the terms change. Any player considering tracking software should read the current terms of the site they intend to play on, because using prohibited software risks account closure and confiscation of funds, not merely a warning.