lab studies / blood suckers
lab study, simulation-based

149 million spins on blood suckers: the highest-RTP slot we have studied still busted 27% of $0.50/$100 sessions

exp · 061 · 2026-06-27 · simulation-based

provider NetEntRTP 98.00%volatility low
at 50c a spin
€507
biggest win
1,014x top win
~80
spins to the bonus
about 16 min at 5/min
€9.00
average bonus
when it hits (18x)
€0.49
avg back per spin
of your 50c
win hit frequency 44.9% (~1 in 2.2 spins)max win 1,014x = €507 (a feature event)
blood suckers is famous for one number: a 98% RTP, among the highest ever published, paired with low volatility. if any slot should be survivable, it is this one, and it is, by a distance, the most survivable game in our library. we simulated 148,798,391 spins of the 98% version. at $0.50 a spin against a $100 bankroll, the bust rate was just 27.4%, a fraction of the 70-86% we see on high-volatility games, and the median session ran the full 2,000-spin cap. but "most survivable" is not "winning": the game is still negative-expectation, more than a quarter of sessions still went to zero, and over the long run the 98% means the house still keeps two cents of every dollar.

Run it yourself in the live simulator. All figures are simulation-based observations, not predictions. See our methodology.

what we measured

parametervalue
provider / engineNetEnt · 5×3 line game, wild + scatter free spins
rtp simulated98.00% (the headline figure; lower operator versions are reported but single-source, not simulated)
volatilitylow
hit frequency44.9% (~1 in 2.2 spins)
stakes$0.20 / $0.50 / $1.00 per spin
bankrolls$50 / $100 / $200
sessions10,000 per stake/bankroll cell, 90,000 total
spin cap2,000 spins per session
max win1,014x stake

a note on this study: we simulated only the 98% headline version. a lower-RTP ladder is reported for blood suckers but currently rests on a single source, so we have not simulated it, when a second source confirms the steps, we will add the version comparison. the bonus trigger rate is not provider-published, so we modelled it (about one free-spins round every ~80 spins) as a documented assumption; the bonus payout distribution and base-versus-feature split are model assumptions calibrated to the published RTP and the 1,014x cap. hit frequency (44.9%) and the 98% RTP are sourced.

how long bankrolls survived

survival curves, share of sessions still alive vs spins played

this is what a high-RTP, low-volatility game does for survival time: at the $100 bankroll the median session ran the entire 2,000-spin cap at both $0.20 and $0.50, and even $1.00 sessions lasted far longer than on a volatile game. the 98% RTP and frequent small wins mean the bankroll erodes slowly rather than collapsing, you get a long, gentle ride. it is still a ride downhill on average.

bust rates

bust-rate grid, share of sessions that busted before the spin cap

bust rates within the 2,000-spin cap, 95% confidence intervals:

$50 bankroll$100$200
$0.20/spin13.9% ±0.70.0% ±0.00.0% ±0.0
$0.50/spin63.3% ±0.927.4% ±0.90.5% ±0.1
$1.00/spin83.2% ±0.762.7% ±0.927.4% ±0.9

plain reading: at low stakes on a healthy bankroll, blood suckers is genuinely hard to bust, $0.20 against $100 or $200 busted essentially never within the cap. but the same fundamentals apply: raise the stake to $1.00/$100 and the majority still bust. high RTP buys you time and a soft landing; it does not flip the maths in your favour.

the bonus wait, and what it pays

on our modelled trigger rate (about 1 in 80 spins, an assumption), the free-spins round is frequent. the payout side (model-based estimates): the average bonus paid 18x stake and the median just 10x, with 93% paying under 50x. blood suckers spreads a high return across many tiny wins and small bonuses, the opposite of a bonus-buy slot, which is exactly why sessions last so long.

what a finished session looks like

final bankroll by percentile

uniquely in our library, blood suckers has a real middle. at $0.50/$100 the median session ended around $68 of the original $100, the 70th percentile kept $116, and the 90th kept $191, a genuine spread of survivable outcomes rather than the die-or-detonate shape of every high-volatility game we have studied. it is the clearest illustration we have of what RTP and volatility actually do: they shape the distribution of how you lose, not whether you lose.

methodology note

we simulate models calibrated to published math, RTP, hit frequency, volatility profile, bonus behaviour, not the provider's game engine. results are sample-based observations from 148,798,391 simulated spins (90,000 sessions), with 95% confidence intervals shown. we simulated the 98% headline version only; a lower-RTP ladder is reported but single-source and not yet simulated. hit frequency (44.9%) is sourced; the bonus trigger frequency is not published and was modelled (~1 in 80) as a documented assumption; the bonus payout distribution and base-versus-feature split are modelled. the base-game ceiling (250x) is a reasoned estimate; max win 1,014x. model validation: blood-suckers v1, analytic calibration exact at 98.00%, 10M-spin check within tolerance. slots are negative-expectation games; nothing here predicts outcomes or improves odds, even at 98%. corrections policy: methodology.html.

Where the max win actually comes from

base 76%
feature 22%

23% of this game's RTP is locked inside the bonus you rarely trigger; the base game on its own returns just 76%.

A normal spin in our simulation never returned more than ~130x (€65). The 1,014x top win is a feature event, it only came out of the bonus. (base-game ceiling: model estimate)

Play the Blood Suckers demo, or stress-test it

Looking for the Blood Suckers demo or free play? A demo shows you a handful of spins. Our free simulator runs Blood Suckers across thousands of sessions and shows what actually happens to a bankroll over time: the bust rate, how long the money lasts, and the wait for the bonus. It is the demo with the math switched on.

stress-test Blood Suckers free

FAQ

Is there a Blood Suckers demo or free play?

Yes. You can play Blood Suckers in demo mode at most casinos, and you can stress-test it free in our simulator, which runs thousands of sessions and reports the bust rate and session length, the demo with the math switched on.

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