2026 Pillar Guide
MustHitBySlotStrategy—TheCompleteGuide
Must-hit-by progressives are the most reliable advantage play opportunity on the casino floor. This guide covers the math, the identification process, the trigger numbers, the walk-away rules, and the specific games where this mechanic appears.
What Is a Must-Hit-By Progressive?
A must-hit-by progressive is a slot machine jackpot that is forced to award before the displayed counter exceeds a published ceiling value. The counter starts at a seed value (the reset), climbs with every wager, and is forced by the game design to trigger before it crosses the ceiling. This is fundamentally different from a standalone or wide-area progressive, where the counter has no ceiling and the trigger is purely random.
The mechanic was popularized in the early 2000s and has since become one of the most common progressive structures on modern casino floors. It appears under many marketing names — Mystery Progressive, Lucky Progressive, By Pays — but the underlying math is the same. The casino has effectively pre-committed to a maximum payout point, and the random selection of when to award the jackpot happens within a known window.
For advantage players, the published ceiling is the entire game. Without it, you cannot calculate expected value — the counter could climb forever. With it, you have a precise upper bound for the integration that determines whether the play is profitable. Every must-hit-by game is, at its core, a uniformly distributed random variable bounded by reset and ceiling, and the AP edge comes from playing only when the current counter is high enough that the average remaining cost to trigger is less than the average remaining payout.
For a deeper conceptual primer, see our trigger value list and the broader must-hit-by mechanic page.
The Math Behind Must-Hit-By
Must-hit-by expected value comes from three numbers and one assumption. The numbers are the current counter, the ceiling, and the contribution rate. The assumption is that the trigger point is uniformly distributed between reset and ceiling — which, for the major manufacturers, is empirically true and confirmed by years of advantage play data.
The Midpoint Formula
On any winning play, the expected remaining jackpot value equals roughly the midpoint between current counter and ceiling. The expected coin-in required to reach the trigger equals (ceiling − current) / (2 × contribution rate). Combined with base game return, the simplified EV per play is:
EV = (current + (ceiling - current) / 2) - (ceiling - current) / (2 * contribution) * (1 - base_RTP)
Worked example: a $1 denomination must-hit-by has a current counter of $850, a ceiling of $1,000, a contribution rate of 1.5% (each $1 wagered adds 1.5 cents to the counter), and a base RTP of 88%. Average remaining payout is $925. Expected coin-in to midpoint is ($150 / 2) / 0.015 = $5,000. House edge cost on that coin-in is $5,000 × 12% = $600. Net EV = $925 − $600 = $325. Strongly player-favorable.
Hold percentage matters because the higher the base game hold, the more it costs to push the counter forward. Two machines at the same trigger threshold can have very different EV if one runs at 88% RTP and the other at 95%. The posted hold is a set number on the glass — read it off the machine and check it against the value on the guide. For more on hold, see the RTP explainer.
The integral version of this formula assumes a uniform distribution across the counter range. In practice, that assumption holds well for Aristocrat, IGT, and Light & Wonder implementations. For multi-tier games, each tier is independent, and total EV is the sum of per-tier EVs minus shared house edge cost. Run each tier through the Must-Hit-By calculator for those situations.
How to Identify a Must-Hit-By Machine on the Casino Floor
A must-hit-by machine is identified by the presence of two visible numbers near the progressive counter: a current value and a ceiling value, often labeled with phrases like "Must Hit By," "Mystery Jackpot Awards Before," or "Win By." If you do not see a published ceiling, the game is not a must-hit-by progressive and the math in this guide does not apply.
Visual Identification Checklist
- Look for a published ceiling. The ceiling is usually shown as a fixed number near the live counter, often in smaller type. Phrases like 'Must Hit By $1,000' or 'Wins By $500' indicate a must-hit-by mechanic.
- Confirm the counter climbs. Watch the counter for 10 to 20 seconds during active play. If the counter increments visibly with each spin, contribution is live. If it appears static, the bank may be in maintenance or you may be looking at a fixed-jackpot game.
- Check for multiple tiers. Many modern must-hit-by games have Mini, Minor, Major, and Grand tiers. Each has its own ceiling. A game with no individual player-favorable tier may still be player-favorable in aggregate when several tiers are simultaneously elevated.
- Note the denomination. The same theme may appear at penny, nickel, quarter, and dollar denominations, each with independent counters. A penny version may be cold while the dollar version next to it is hot.
- Check the bank for linked progressives. Many must-hit-by games are linked across a bank of cabinets. The counter you see at one seat reflects play across the entire bank. This raises contribution rate and creates faster counter climbs.
Our deeper guide on reading slot machine counters walks through the visual cues for every major manufacturer's must-hit-by display style.
The Trigger Number: When to Sit Down
The trigger number is the counter value at which a specific game tips in your favor to play. It is unique to each game and depends on the ceiling, the contribution rate, and the base RTP. Memorizing trigger numbers for the games you target on a given casino floor is the single highest-leverage thing you can do as a must-hit-by player.
For most popular games, the trigger sits somewhere between 80% and 92% of the way from reset to ceiling. A $5-to-$1,000 must-hit-by with a 2% contribution and 90% RTP tips in your favor at roughly the $880 mark. The same game range with a 1% contribution and 88% RTP doesn't tip in your favor until the counter is past $940. Small parameter changes shift the trigger substantially — never assume the trigger from one game applies to another.
The fastest way to get an exact answer is to enter the four parameters into our must-hit-by EV calculator. Punch in current counter, ceiling, contribution rate, and base RTP, and it returns the expected profit, the expected coin-in to trigger, and the breakeven counter point. Use it for every play before sitting down.
For machines with multiple progressive tiers, the trigger calculation involves all tiers simultaneously. Sometimes no individual tier is a play but the aggregate is — see our trigger points reference for trigger ranges on the most-played multi-tier titles.
The Walk-Away Rule
The walk-away rule for must-hit-by is simple: once you sit down and start playing, you do not stand up until either the jackpot triggers or your dedicated stop-loss bankroll for that play is exhausted. Leaving early gifts your contributions to the next player.
- Set the stop-loss before sitting down. Compute the expected coin-in to trigger and double it. That doubled number is your variance buffer — most plays trigger before that point, but some don't.
- Do not chase variance. If the counter hasn't moved into the trigger zone you expected, the trigger may simply be in the upper tail of the distribution. Continue playing until the stop-loss or the trigger.
- Do not extend the stop-loss. If you blow through the buffer and the jackpot still hasn't triggered, you got unlucky. Stand up and walk away. The next player gets a more winning play than you had.
- Do not abandon a player-favorable machine for a better one mid-play. The contributions you've already made are sunk; they don't transfer. Finish the current play first, then move.
This rule is uncomfortable in practice. It feels wrong to keep feeding a machine when you're $200 down and the counter has barely moved. But the math is the math: every spin beyond breakeven is still player-favorable in expectation, even if the variance is punishing. See walk-away rules in depth for variance management techniques.
Common Must-Hit-By Machines
Six machine families account for the majority of must-hit-by play across North American casino floors. Each has slightly different mechanics, contribution rates, and ceiling ranges — but all share the core must-hit-by structure.
Buffalo Link / Lightning Link / Dragon Link
The Aristocrat link family. Four-tier must-hit-by progressives (Mini, Minor, Major, Grand) on a hold-and-spin base. Buffalo Link and Lightning Link are the two most-played AP titles in North America.
Lightning Link Strategy
The original of the Aristocrat link family. Bonus-style hold-and-spin with cascading must-hit-by tiers and persistent value across the bank.
Dragon Link Strategy
Higher-volatility cousin of Lightning Link. Tighter base RTP and higher Grand ceilings make tier evaluation slightly more demanding.
Rich Little Piggies
IGT's classic must-hit-by family. Variants include Big Spender and Meal Ticket. Single-tier Mystery jackpot with very predictable ceilings.
Piggy Bankin'
WMS-era classic that has aged into a Light & Wonder must-hit-by staple. Counter-driven hybrid with a must-hit-by progressive on top of an accumulator base.
Mighty Cash
Aristocrat's hold-and-spin must-hit-by line. Multiple themed cabinets (Madonna, Tiger, Wonder 4) all share the underlying mechanic.
Dollar Storm
IGT's modern multi-tier must-hit-by. Includes Emperor's Treasure, Lucky Lions, and Ninja Moon variants. Aggressive contribution rates create fast-climbing counters.
Ocean Magic
IGT classic with hold-and-spin features and a must-hit-by progressive layer. The Grand variant adds a four-tier MHB on top.
Manufacturer Coverage
Three manufacturers produce the overwhelming majority of must-hit-by games on North American floors. Each has a slightly different design philosophy — counter increments, ceiling structures, and tier counts vary materially between vendors.
Aristocrat
The Link family (Buffalo Link, Lightning Link, Dragon Link) and Mighty Cash. Famous for tight, predictable contribution rates and well-proven ceiling ranges.
IGT
Rich Little Piggies, Dollar Storm, Ocean Magic. IGT must-hit-by games are notable for higher base RTPs and slightly slower counter climbs.
Light & Wonder
Piggy Bankin', Huff N' Puff, and Wheel of Fortune progressives. Often hybrid designs that combine a must-hit-by layer with an accumulator or counter mechanic underneath.
Aristocrat AP Deep-Dive
Game-by-game breakdown of every Aristocrat title with advantage play potential, including trigger ranges and bank counts.
Bankroll for Must-Hit-By
Must-hit-by bankroll requirements scale with two factors: the cost-to-trigger of the biggest game you'll play, and your tolerance for risk-of-ruin during a bad run. A conservative starting point is three to five full plays at the maximum-coin-in machine you target. For penny denomination Buffalo Link, that's a few hundred dollars. For dollar denomination Dollar Storm, that can run into five figures.
Bankroll Allocation Tiers
- Recreational AP ($500 to $2,000): Stick to penny and nickel must-hit-by games. Buffalo Link, Lightning Link, Piggy Bankin' on penny.
- Serious AP ($5,000 to $15,000): Quarter and dollar must-hit-by become accessible. Add Rich Little Piggies, Mighty Cash, Ocean Magic Grand to the rotation.
- High-volume AP ($25,000+): Multi-machine simultaneous play, dollar+ denominations, multi-tier games like Dollar Storm and Wonder 4 Boost Gold become viable. Variance is significant.
To size your bankroll for a specific risk-of-ruin target, work through our bankroll management guide for a complete framework on session sizing, stop-losses, and reinvestment policy.
Frequently Asked Questions
Must hit by means the progressive jackpot is forced by the game's pay tables to award before the counter exceeds a stated ceiling value. The counter starts at a reset (the seed) and climbs as players wager. The game's random selection of the trigger point happens in advance and lies somewhere between the reset and the ceiling. Once the counter passes that hidden trigger, the next qualifying spin awards the jackpot. Because the ceiling is published on the glass, you know the maximum the counter can ever reach — which lets you calculate expected value precisely.
Use the midpoint method as a quick estimate. Take the current counter, find the midpoint between current and ceiling (current + (ceiling - current) / 2), then add the base game return on the coin-in needed to reach that midpoint. Subtract the coin-in. If the result is positive, the play is player-favorable. The Run the Slots MHB Calculator at /calculators/mhb runs the exact integral version of this calculation in seconds and tells you the expected profit and the expected coin-in required.
Trigger numbers vary by game and denomination. As a rule of thumb, you generally want the counter to be above 80 to 90 percent of the way from reset to ceiling before the play tips in your favor. Some games with high base RTP tip in your favor earlier (around 70 percent of the range). Games with low base RTP and small jackpot ranges may not tip in your favor until the counter is within a few dollars of the ceiling. Always run the math — never assume.
Yes. The trigger point belongs to the machine, not to you. If you walk away from a player-favorable must-hit-by machine before the jackpot triggers, the next player who continues betting will collect when the counter crosses the trigger. This is why discipline matters: once you commit to a play, you must continue until the jackpot hits or your stop-loss bankroll is exhausted. Walking away from a winning play wastes the contributions you already made.
Yes, completely legal. You are simply playing the game as designed using publicly displayed information — counter values and ceiling values printed on the glass. No casino rule prohibits this. You are not modifying the machine, not colluding, and not cheating. You are simply choosing when to play based on the math the casino itself has published.
Bankroll requirements depend on the cost-to-trigger and the variance of the base game. A conservative rule is to have enough bankroll to fund three to five full plays at the highest-coin-in machine you target. For a $1 denomination machine that takes $400 of expected coin-in to reach the midpoint, that means $1,200 to $2,000 in dedicated bankroll. The Run the Slots Bankroll Calculator helps size this for your specific game and risk tolerance.
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