The two most common poker stats are VPIP and PFR and, typically, they're displayed together. For example, when you read that a player is "18/15" it means that he has a VPIP of 18% and a PFR of 15%.

Some stats are expressed as a percentage (like VPIP and PFR) while others aren't (like AF or Nb hands), which can be confusing. Poker Lens always display a (%) hint for stats that are percentage.

Some stats only concern preflop actions (for example VPIP, PFR, PF3B, limp/fold, ATSB, etc.)
but they do **not** all have their name starting with "PF" (for example VPIP, ATSB, etc.).
For every stat defined here we indicate if it is a preflop or postflop stat.

In some cases Poker Lens is using a slightly longer or more descriptive stat name, as to eliminate common sources of confusion. One such example is the "$EV diff" (more below). The "$EV diff" doesn't mean much to newcomers for both "$ - $AIEV" and "$AIEV - $" are, indisputably "$EV differences". Hence Poker Lens simply names that stat "$ - $AIEV", which doesn't let any room for confusion. Another example is Poker Lens's PFB-vs-PF3B: fold%/call%/raise% (more below) stats. We believe that those slightly longer and more descriptive names are less confusing than other alternatives.

VPIP: Voluntary Put (money) In Pot (sometimes *"Voluntary Put $ In Pot"*). The percentage
of hands where one voluntary puts money in the pot: it is "voluntary" because blinds and antes
are excluded from the computation.

Formula: *(hands where player did voluntary put money in) / (hands played)*

Note that it is nearly always possible to voluntarily put money in the pot, so this stat concerns nearly every hand played, which is why this stat tends to quickly be representative.

The VPIP carries no meaning of "aggressivity": it doesn't differentiate between preflop calls and preflop raises. What the VPIP tells is if someone is tight or loose preflop.

PFR: Pre-Flop Raise. The percentage of hands a player made any raise preflop.

Formula: *(hands where player did raise preflop) / (hands played)*

These two stats are by far the most common ones and the ones that converges the fastest. They're nearly always displayed together: when someone says that someone is "18/16" it means he voluntary puts money in pot 18% of the time and raises preflop 16% of the time.

By analyzing the VPIP and the PFR, you can already see your opponent's preflop style: you can see if he's tight/passive, tight/aggressive, loose/passive or loose/aggressive.

PF3B: Pre-Flop 3-bet. The percentage of hands a player re-raises preflop when he has the opportunity to do so.

Formula: *(hands where player did re-raise preflop) / (hands where player had the opportunity to re-raise preflop)*

The PF3B stat is one of the most important one: it is not uncommon to have your HUD set up to display VPIP/PFR/PF3B (VPIP/PFR/AF or VPIP/PFR/AFreq are common too).

Note that if someone calls preflop then gets raised and then re-raise, this is not
considered a PF3B (see *limp-vs-raise:raise%* stat).

The PF3B converges relatively fast but still takes longer to converge than the VPIP or the PFR for a player doesn't have the opportunity to do a PF3B in every hand he plays.

ATSB: Attempt To Steal Blind. The percentage of hands where a player tries to "steal" the blinds when he has the opportunity to do so.

Formula: *(hands where player did open-raise preflop from CO/BTN/SB) / (hands where player had the
opportunity to do so)*

Someone has the opportunity to steal the blinds when he's in the cut-off, button or small blind and everyone folds to him: if he then does a preflop-raise it is considered to be an ATSB.

Note that when someone does an ATSB, this raises both his ATSB and his PFR stat.

(preflop) Preflop-Raise versus preflop-reraise: {fold, cold, raise}. The percentage of hands where a player is first to raise preflop, then gets re-raised then folds, calls or re-re-raise.

Poker Lens offers three stats concerning the first preflop raiser facing a reraise (that is: facing a PF3B). When the first preflop raiser gets re-raised and can speak again, he'll typically (*) have three possibilities: fold, call or raise.

# PFR-vs-PF3B: fold%

# PFR-vs-PF3B: call%

# PFR-vs-PF3B: raise%

Formula for PFR-vs-PF3B: fold% * (hands where player did raise first preflop then folded preflop) / (hands where player did raise first preflop then got re-raised) *

Formula for PFR-vs-PF3B: call% * (hands where player did raise first preflop then called preflop) / (hands where player did raise first preflop then got re-raised) *

Formula for PFR-vs-PF3B: raise% * (hands where player did raise first preflop then re-re-raised preflop) / (hands where player did raise first preflop then got re-raised [but not all-in]) *

(*) When the first PFR gets re-raised all-in and can speak again, he only has two possibilities: fold or call.

These three stats are very useful and are **much** better than the simpler "PF4B" stat. Typically, you care
much more about how an opponent that is the first to raise preflop will react to a re-raise (that is, to a PF3B)
than about what an opponent's overall "PF4B" is. And these three Poker Lens stats allows you to see how often
someone that is the first to raise preflop folds/calls/raise when facing a preflop re-raise.

Minor nitpick: The 'PFR' in this stat really means 'first to PFR' (which should be implied by the fact that only the first player to PFR can be facing a PF3B but we still wanted to state this ;)

(preflop) Preflop-re-raise vs preflop-re-re-raise: {fold, cold, raise}. The percentage of hands where a player that did PF3B gets raised then folds, calls or raise again.

# PF3B-vs-PF4B: fold%

# PF3B-vs-PF4B: call%

# PF3B-vs-PF4B: raise%

This stat will converge much slower than *PFR-vs-PF3B...* because a preflop re-re-raise is
much less common than a preflop re-raise. You do really need quite some hands on an opponent
for these three stats to be valuable.

(preflop) limp-vs-raise: {fold,cold,raise}. The percentage of hands where a player limps preflop then {folds,cold,raise} when he has the opportunity to do so.

Some players, especially at lower limits, like to "limp" a lot (limping means entering a pot by just calling the minimal amount, which is typically the big blind amount). Some others like to limp-reraise monster hands, etc.

Poker Lens offers three stats concerning limpers facing a raise: a limper enters the pot by just calling the minimal bet amount and someone does a raise preflop. The limper now has the opportunity to speak again and has three options: fold, call or re-raise.

# limp-vs-raise: fold%

# limp-vs-raise: call%

# limp-vs-raise: (re)raise%

Formula for limp-vs-raise: fold *(hands where player did limp then fold preflop) / (hands where player had the
opportunity to do so)*

Formula for limp-vs-raise: call *(hands where player did limp then call preflop) / (hands where player had the
opportunity to do so)*

Formula for limp-vs-raise: (re)raise *(hands where player did limp then re-raise preflop) / (hands where player had the
opportunity to do so)*

Flop CBet. Flop Continuation Bet. How often a player that is the last preflop raiser bets the flop when he has the opportunity to do so.

Formula: *(hands where player did raise last preflop bets first preflop) / (hands where player
had the opportunity to do so)*

The last person to raise preflop cannot always do a continuation bet on the flop: if another player bets first the flop (that is: the other "donkbets" the flop) then there cannot be a flop continuation bet anymore.

Flop CBet OOP. Flop Continuation Bet Out Of Position. How often a player that is the last preflop raiser and the first to speak at flop bets.

Formula: *(hands where player did raise last preflop and speak first at flop does bet the flop) / (hands where player is last to raise preflop)*

Flop CBet IP. Flop Continuation Bet In Position. How often a player that is the last preflop raiser and the last to speak at flop does bet the flop when it is checked to him.

Formula: * (hands where player did raise last preflop and speak last at flop does bet the flop) / (hands
where player is last to raise preflop and last to speak at flop ) *

Flop Donkbet. How often a player that is **not** the last preflop raiser bets before the last
preflop raiser speaks.

Formula: * (hands where player does bet the flop) / (hands where player speaks before the
last player that raised preflop) *

(postflop) Went To Showdown (When Saw Flop). The percentage of time a player that sees the flop goes to showdown.

Formula: * (number of showdown seen) / (number of flop seen) *

This stat typically needs to be analyzed along with the W$WSF and W$SD stats.

(postflop) Won $ When Saw Flop. The percentage of time a player wins when he sees the flop.

Formula: * (number of hands won postflop) / (number of flop seen) *

This stat takes into account both the postflop hands where the player won without going to showdown (because the player bet or raised postflop and everyone folded) and those going to showdown.

Poker Lens supports multiple currencies but even on, say, Euro tables, the stat's name stay W$WSD ;)

(postflop) Won $ at Showdown. The percentage of time a player wins the pot when the hand goes to showdown.

Formula: * (number of hands won at showdown) / (number of showdown seen) *

(preflop) Big Blind vs attempt to steal blind. The percentage of time a player folds his big blind to a steal (see ATSB%).

Formula: * (number of hands where player folds his BB when there's an ATSB) /
(number of hands where player is the BB and there's an ATSB) *

This stat is useful to determine if a player is likely to give up is big blind or not when another one is trying an "attempt to steal blinds" (see ATSB%).

Stack in Big Blind. The amount the player had before the deal, expressed in number big blinds. For example if a player is sitting with $100 at a $100 No-Limit table, where blinds are $0.50/$1, he has 100 big blinds.

This stat is mostly useful for tournaments/SnG players, where the blinds amounts go up at each new level.

(postflop) Aggression Factor. This stat is *not* a percentage.

Formula: * (nb raises + nb bets) / (nb calls) *

This stat only takes into account postflop bets, raises and calls.

This stat is one measure of the overall aggressivity of a player postflop. Note that it does not take checking neither folding actions into account (see AFreq%).

(postflop) AFreq. Aggression Frequency. Agg Freq%. AFq%

Formula: * (nb raises + nb bets) / (nb raises + nb bets + nb calls + nb folds) *

This stat is one measure of the overall aggressivity of a player postflop. Note that contrarily to the AF stat, folding actions are taken into account.

'checking' actions aren't taken into account (see AFreq2%)

This is the original 'aggression frequency' stat, that does *not* take checking
actions into account. If you want checking actions to be taken into account, you must
use the AFreq2% stat.

This is slightly confusing, but online poker players have agreed on two different AFreq% formula and both have their merits and their proponents, which is why Poker Lens offers the choice between both of them.

(postflop) AFreq2%. Aggression Frequency, including checks.

Formula: * (nb raises + nb bets) / (nb raises + nb bets + nb calls + nb folds + nb checks) *

This stat is similar to AFreq%, but it also takes the checks into account.

M-factor (also called "M-ratio" or just "M") is a tournament concept invented by Paul Magriel. Harrington studied the concept and came up with the "Effective-M" and the concept of zones.

Formula: *stack / (small blind + big blind + total antes)*

Tournament players can read more about the M-factor on Wikipedia.

Poker Lens allows to color-code any stat depending on its value, hence you can display the M-factor and
use the *HUD Layout Editor*'s color range editor to assign the Harrington zone colors depending on
the M.

This is the modified M-factor created by Harrington, that takes into account the change in dynamic at a table where there are less and less players (like on a final table of a tournament).

The *"Stack in BB"*, M and *Effective-M* stats are nearly exclusively used by tournament players. If you
play both tournaments and cash games, we advice you to create two different layouts: one for the cash games and
the other for the tournaments.

There are a few corner cases that can influence some stats a tiny bit:

For example if the cut-off (CO) pays a penalty blind, and it is folded to him and he checks and then the player on the button (BTN) does a preflop-raise, is the button's preflop raise considered an "Attempt To Steal Blind" (ATSB)?

There are a some other scenario where the formula given for a given stat may seem not precise enough. Most of these corner cases are however very uncommon and do not influence the various stats very much at all, which is why we advice to not care too much about such details.

Now if you have a doubt about a stat appearing in the tracker or in the HUD don't hesitate to ask in the forum (or by email).