A-Z Reference

Advantage Play Glossary

Every term you need to know as a slot machine advantage player. 38 definitions with clear explanations and links to in-depth guides.

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A

Accumulator: A slot machine that collects or banks a resource (coins, orbs, counters) over time toward a bonus trigger. Previous players' progress carries over, creating advantage play opportunities when the accumulated value is high enough.; Accumulator Slots Guide
Advantage Play (AP): The practice of using math, observation, and legal strategies to identify and play slot machines with a positive expected value. AP players only play when the numbers are in their favor.; What Is Advantage Play?

B

Bankroll: The total money a player has allocated specifically for advantage play sessions. Proper bankroll management ensures you can survive the natural variance of +EV play without going broke.; Bankroll Management Guide
Banked Bonus: A bonus feature that saves progress between players. When a previous player leaves a machine with a partially filled bonus meter, the next player inherits that progress — the core mechanic behind most accumulator advantage plays.
Base Game: The regular slot game excluding progressive jackpots and bonus features. The base game return is typically 85-92% for modern slots, with the remaining return coming from bonuses and progressives.
Base Game Return: The expected payback percentage of the slot's regular spins, excluding progressive contributions and bonus features. Knowing this helps calculate total RTP when adding progressive and bonus value.

C

Ceiling: The maximum value a must-hit-by progressive can reach before it is guaranteed to pay out. The closer a progressive gets to its ceiling, the higher the expected value of playing that machine.; MHB Progressives Explained
Coin-In: The total amount of money wagered on a machine, not the same as money lost. A player who bets $1,000 in coin-in may only lose $50 if the machine returns 95%. Used to calculate meter rates and track session costs.
Counter: A visible or hidden tracker on a slot machine that accumulates toward triggering a feature. Counters may display as collected items, filled meters, or numerical values. When a counter is elevated, the machine may be in a +EV state.; How to Read Meters

E

EV (Expected Value): The mathematical average outcome of a bet calculated over infinite repetitions. Positive EV (+EV) means the play is profitable long-term; negative EV (-EV) means the house has the edge. AP players only take +EV plays.; How to Calculate EV

F

Floor: The starting or reset value of a progressive meter — the lowest point it returns to after a jackpot hit. The distance between the floor and the current meter value indicates how much has been contributed by players since the last hit.
Floor Walk: Scouting the casino floor for machines in +EV states without playing. Experienced AP players develop efficient walk routes through a casino, checking meters and counters on known advantage play machines.; Casino Floor Strategy
Free Games: Bonus rounds with free spins accumulated by previous play. On some machines, free games are banked and carry over between players, making them a type of accumulator advantage play.; Free Games Accumulator Slots

G

Grind: The process of playing through +EV situations repeatedly over many sessions. AP is often a grind — small edges played consistently add up to meaningful profit, but individual sessions can be losing ones.

H

Hold: The percentage of coin-in that the casino keeps. A machine with 8% hold returns 92% to players (92% RTP). Hold is the inverse of RTP.
Hold & Spin: A bonus feature common in link-style games where locked symbols remain on screen while remaining positions spin for a set number of respins. Popular in games like Lightning Link, Dragon Link, and Buffalo Link.; Dragon Link Strategy
House Edge: The casino's built-in mathematical advantage on a game, expressed as a percentage. On a slot with 92% RTP, the house edge is 8%. Advantage play temporarily reverses this edge on specific machines in specific conditions.

L

Linked Progressive: A progressive jackpot fed by multiple machines, causing faster meter growth than standalone progressives. Linked progressives across a bank of machines or an entire casino floor reach +EV thresholds more quickly.
Link Game: Slot machines featuring hold-and-spin bonus mechanics, typically with progressive jackpots. Examples include Lightning Link, Dragon Link, Buffalo Link, and Mighty Cash. Many link games offer advantage play opportunities through their progressive structures.

M

MHB (Must-Hit-By): A progressive jackpot guaranteed to trigger before reaching a specified ceiling value. MHB progressives are the most mathematically analyzable form of advantage play because the ceiling creates a known upper bound for expected cost calculations.; MHB Strategy Guide
Meter: The display on a slot machine showing the current value of a progressive jackpot or accumulated bonus counter. Reading meters accurately and quickly is a foundational skill for advantage players.; How to Read Slot Machine Meters
Meter Rate: How fast a progressive meter increases per dollar wagered, expressed as cents per dollar of coin-in. A meter rate of $0.50 per $100 coin-in means the progressive grows by half a cent per dollar bet. Lower rates mean slower growth and higher cost to reach breakeven.
Midpoint Method: A calculation technique for MHB progressives that estimates the breakeven point by finding the statistical midpoint between the current meter value and the ceiling. Assumes uniform trigger distribution — in practice, some games may be biased toward triggering near the ceiling.; MHB Strategy Guide

N

Negative EV (-EV): A situation where the expected mathematical outcome is a net loss. Most slot machines are -EV most of the time. Advantage players avoid -EV plays entirely — the discipline to walk away from -EV is what separates AP from gambling.

P

Persistent State: A game feature that carries over between player sessions, such as collected wilds, counter values, or bonus progress. Persistent state mechanics are what make advantage play on slots possible — without them, every spin would be independent and always -EV.; Persistent State Slots Guide
Progressive Jackpot: A jackpot that increases with each bet placed, funded by a small percentage of each wager. Progressives can be standalone (single machine) or linked (multiple machines). When a progressive grows high enough above its reset value, the added value can push the total RTP above 100%.; Progressive Jackpot Guide

R

Reset Value: The value a progressive meter returns to after being won. Also called the floor or seed value. The difference between the current meter and the reset value represents the player-funded excess that contributes to advantage play opportunities.
RTP (Return to Player): The theoretical percentage of wagered money returned to players over time. A 95% RTP means $95 returned per $100 wagered on average. RTP above 100% indicates a +EV situation.; Slot Machine RTP List

S

Session: A single play period on one machine. AP sessions are typically short — play only while the machine is +EV, then leave. Long sessions grinding through -EV territory is gambling, not advantage play.
Session Bankroll: The amount allocated for a single playing session, separate from total bankroll. Session bankroll limits protect the overall bankroll from a single bad variance run.; Bankroll Management Guide
Standalone Progressive: A progressive jackpot fed only by the individual machine, as opposed to a linked progressive shared across multiple machines. Standalone progressives grow more slowly but the meter value is entirely attributable to play on that specific machine.

T

Threshold: The specific meter value or counter level at which a machine transitions from -EV to +EV. Run the Slots calculates trigger thresholds for every supported machine based on base game return, meter rates, and bonus values.; Trigger Points Guide
Trigger: The specific condition that activates a bonus feature or progressive payout. In AP context, the trigger point is the threshold where playing the machine becomes mathematically profitable.; Trigger Points Guide

V

Variance: The natural fluctuation of actual results around the expected value. High variance means bigger swings between wins and losses. Even +EV plays can produce losing sessions due to variance — bankroll management accounts for this.
Volatility: How much results vary from the expected return in the short term. High volatility slots have infrequent but large payouts; low volatility slots pay smaller amounts more often. For AP, higher volatility means you need a larger bankroll to survive the swings.
Vulture / Vulturing: The practice of finding and playing machines left in +EV states by previous players who didn't realize the value they'd built up. The term comes from the player 'swooping in' to collect value that others left behind.

W

Walk / Walk Away: The discipline of leaving a machine or a casino when conditions are not favorable. Walking away from -EV situations — even when you're 'due' for a win — is the single most important habit in advantage play.
WAP (Wide Area Progressive): A progressive jackpot linked across multiple casinos, such as Megabucks. WAPs grow extremely fast due to high volume but are rarely viable for AP because the base game return is very low and the trigger probability per spin is tiny.

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