Roulette maths · Inna practice · 7 minute

Ow long di session las an wah it cost

Ow long a bankroll last at a set stake, an wah di hour dem cost. Di numba dem weh most playa neva work out, an weh most a dem fi work out.

Short ansa

Flat even-money bettin last, pon average, 37 spin fi evry stake inna di bankroll, even doh half a all session done sooner dan dat; di expected cost evry hour a stake × spin a hour / 37. Togedda dem mek yuh put a price pon a evenin bifo it start.

even-money time to ruin
37 × B/s spin, pon average
$500 at $10
≈ 1,364 spin, median
cost evry hour
s × spin/h / 37
$10 at 50/h
$13.51 a hour

Ow long a bankroll last

Wid bankrollmoney mattaBankrollAll di money yuh set aside fi play. Fi manage yuh bankroll mean yuh decide ow much a it yuh a go risk pon evry bet an evry session.Read di whole ting → B an flat even-money stake s, di bankroll drif dung by s/37 a spin pon average an swing by bout s a spin one way or di odda. Di drif alone set di average: di bankroll last 37 × B/s spin, cause dat a ow long it tek fi lose B at s/37 a spin. Di swing dem mek di length dem uneven. Some session dead early pon a bad run, a few last far longa, an di median, di length weh half a all session cyaan reach, deh unda di average. A $500 bankroll at $10 (B/s = 50) last 1,850 spin pon average an 1,364 at di median, bout 27 hour at a live table. At $50 (B/s = 10) di median a 136 spin, unda tree hour.

bankrollstakeB/smedian spin to ruin (even money)at 50 spin/haverage spin to ruin
$500$51003,134≈ 63 hour3,700
$500$10501,364≈ 27 hour1,850
$500$2520394≈ 8 hour740
$500$5010136≈ 2 hour 45 minute370
$500$100541≈ 50 minute185
$100$1010136≈ 2 hour 45 minute370
Exact, flat bettin pon red pon a European wheel wid nuh stop rule. Straight-up bettin ruin yuh faasta pon evry row cause di variance higha.
Same bankroll, same stake: some session done early, a few run very long, an di median fall short a di average.

Wah di hour dem cost

Expected lossmathsExpected lossExpected value times all di money yuh bet; di average amount yuh lose ova a session or a period (di loss yuh fi expec pon average).Read di whole ting → evry hour = stake × spin a hour / 37. Di two numba weh yuh control a di stake an di pace. A $10 bettor at 50 spin a hour pay $13.51 a hour pon a European table, $6.76 pon a French table, $27 pon a speed table. Decide wah one hour a roulette worth to yuh, an di stake follow fram dat.

Expected loss evry hour at $10 a spin$ a hour
Casino floor · 40/h
$10.81
Live table · 55/h
$14.86
Speed live · 100/h
$27.03
RNG · 200/h
$54.05
$ a hour
027.03$54.05
stake × spin a hour / 37. Di pace a di bigges lever pon wah a hour cost.

French roulette

Put dem togedda

A playa wid $500 weh waan a four-hour evenin at a 50-spin live table (200 spin) an nuh waan go bus fi stake nuh more dan bout $25 (B/s = 20, median ruin 394 spin). Di expected cost a di evenin a 200 × $25 / 37 = $135. If $135 too much, di stake drop an di evenin get safer an cheaper same time: at $10, expected cost a $54 an ruin bifo 200 spin rare.

Twelve four-hour evenin, $500 at $25 pon redresult versus di start
+$1,050$0−$500+$400−$2500125250375500spinresult
1,000 session × 500 spin · violet p10/p25/p75/p90, light blue median, 82 faint sample · move ova di chart fi see di quantile dem at a spin
  • p10 −$500
  • p25 −$500
  • median −$500
  • p75 −$50
  • p90 +$350
1,000 session × 500 spin · y-axis cut to di 1st–99th percentile (di extreme dem: −$500 to +$1,700) · 500 spin · $25 base · even-money bet
Expected end: −$135. Most a di line dem survive; bout one evenin outta four touch zero. At $10 bout one outta 700 wudda touch it.

Straight-up session

Fi straight upbet demStraight upOne single numba, pay 35:1.Read di whole ting → di stake haffi smalla fi di same session length: σ fi evry unitmoney mattaUnitDi base stake weh a system or a playa work wid. Dem describe progression inna unit suh dem work at any table.Read di whole ting → a 5.84 gainst bout 1 fi redbet demRedEven-money bet pon di 18 red numba. Inna French: rouge.Read di whole ting →, suh di bankroll haffi cova long dry spell. A median a 200 spin need B/s a bout 13 pon red an bout 56 pon one single numba, roughly four time as much stake. A $500 bankroll weh fi last 200 spin a straight up at di median need a stake near $9. Playa weh bet $25 straight up fram $500 a buy a short, loud evenin: twenty miss inna a row end it, an dat happen more often dan not.

Di honest price list

Roulette cost stake × spin / 37. Evryting else, di system, di lucky numba, di hedge, decide di shape a di evenin an nuh it price. A playa weh work out di price fus an choose a stake weh dem happy fi pay done di only piece a strategy weh work.

Formula

E[cost evry hour] = s × spin/h / 37
average spin to ruin = 37 × B/s fi even money
straight up: multiply di B/s yuh need by ≈ 4

Question dem

A simple formula deh fi di median?

Nuh one weh exact. Fi a small bankroll di swing dem run tings an di median grow roughly like (B/s)², same as fi a fair coin. Fi a big one di edge run tings an di median come close to di average, 37 × B/s. At bout 20 stake di (B/s)² rule jus happen fi match di exact median, 394 spin; unda dat it come out short an ova dat it come out long.

A stop-loss change di cost?

It put a cap pon di wors case an mek di session shorta, an dat cut di expected loss inna proportion to di spin dem yuh neva play.

Wah bout la partage?

It cut di cost evry hour inna half pon even-money betbet demEven-money betRed/black, odd/even, high/low. 18 numba, pay 1:1.Read di whole ting → an double di average time to ruin, to 74 × B/s spin.

Fun wid maths

Try dem yuhself fus. Evry ansa fold up; open it wen yuh ready.

  1. Yuh bet $500 pon redbet demRedEven-money bet pon di 18 red numba. Inna French: rouge.Read di whole ting →, $10 at a time, pon a European wheel, wid no rule fi stop. Pon average, ow much spin di bankrollmoney mattaBankrollAll di money yuh set aside fi play. Fi manage yuh bankroll mean yuh decide ow much a it yuh a go risk pon evry bet an evry session.Read di whole ting → last?

    Show di ansa

    Ansa 1,850 spin: 37 spin fi each a di 50 stake.

    Each spin cost, pon average, 1/37 a di stake: $10/37, bout 27 cent. Di bankroll hold 50 stake, an fi lose 50 stake at 1/37 a a stake a spin tek 50 × 37 = 1,850 spin.

    Di swing dem nuh change dis average, cause a session can only end at zero an evry spin bifo dat cost di same 27 cent pon average. Wah dem change a di spread: half a all session done by spin 1,364, an bout one outta twenty run past 5,000, an dat pull up di average.

    Epstein (2013) give di general rule: gainst a house weh neva run outta money, a bankroll a z stake last z divide by di edge pon each spin. Pon a American wheel, weh even money lose 1/19 a di stake a spin, di same $500 last 950 spin pon average.

Sumting fi laugh

Stake × spin / 37. Put a price pon di evenin bifo it start.

Stake × spin / 37. Put a price pon di evenin bifo it start.

Source dem

  1. Feller, W. An Introduction to Probability Theory and Its Applications, Vol. 1. Wiley, 3rd ed., 1968. Gambla ruin, chapta XIV.
  2. Ethier, S. N. The Doctrine of Chances: Probabilistic Aspects of Gambling. Springer, 2010. Chapta 13, roulette.
  3. Epstein, R. A. The Theory of Gambling and Statistical Logic, 2nd ed. Academic Press, 2013.
wi check it 2026-09-28model: European wheel, single zeroow wi work it out ↗source dem ↗