Sample Size
Kitne spins ke baad kisi pattern ka koi matlab hota hai.

Kisi pocket ko 37 mein 1 ki jagah 30 mein 1 baar aate hue theek-thaak confidence se pakadne ke liye lagbhag 4,400 spins chahiye. 35 mein 1 wala pocket, jo sach mein paisa dila sakta hai, lagbhag 70,000 spins leta hai.
Itne zyada kyun
Signal, yaani har hazaar spins mein kuch extra hits, √(n·p·(1−p)) ≈ √(n/37) ke binomial noise ke muqable chhota hai. Noise 1/√n ki tarah girta hai, isliye uncertainty aadhi karne mein chaar guna spins lagte hain. 1/30 wala pocketsaamanPocketRotor ke 37 numbered khaanon mein se ek. Doosre naam: slot, cup.Poora padhein → har hazaar mein 33 hits deta hai jabki expected 27 hain: chhe extra hits, aur standard deviationganitStandard deviationVariance ka square root; expected value se kisi result ki aam doori.Poora padhein → lagbhag paanch. Hazaar ka ek sample in dono ko bharose se alag nahi kar sakta.
Formula
Ek pocket ke one-sided test ke liye, 5% level aur 80% power par, zaroori n lagbhag ((1.645·√(p₀(1−p₀)) + 0.84·√(p₁(1−p₁))) / (p₁ − p₀))² hai, jahan p₀ = 1/37 aur p₁ shak wala rate hai. Yeh pehle se chune gaye ek pocket ke liye sahi hai. Agar aap sabse garam pocket dhoondhne ke liye saare 37 pockets scan kar rahe hain, toh false-positive rate imaandaar rakhne ke liye lagbhag do se teen se guna kijiye.
Practical matlab
300 spins ke baad hot numbermythHot numberAisa number jo haal mein expected se zyada baar aaya hai. Fair wheel par yeh kuch predict nahi karta.Poora padhein → noise hai. 3,000 ke baad woh usi wheel se 3,000 aur collect karne ki wajah hai. 30,000 ke baad woh shayad aisa wheel hai jise physically measure karna worth hai. History mein har documented bias exploit das-hazaaron record kiye gaye spins par bana tha, aur har ek mein mahine lage.
Data ki keemat
50 spins per ghante par, 10,000 spins matlab 200 ghante ki recording, ya kai hafton tak published histories copy karna, ek hi pehchaane gaye wheel headsaamanWheel headRotor ka doosra naam: numbers wala ghoomne wala hissa.Poora padhein → se, jise casino ne is beech na ghumaya ho na re-fret kiya ho. Statistics nahi, balki yahi wajah hai ki bias play khatam ho gaya: maintenance cycle data-collection cycle se chhota hai.
Khud edge ke liye sample size
Yahi arithmetic batata hai ki player ko apne results mein house edgeganitHouse edgeHar stake ka woh hissa jo casino average mein rakh leta hai: European roulette mein 2.70%.Poora padhein → dekhne mein kitna time lagta hai: ek sigma ke liye lagbhag 1,400 even-money spins, aur edge ke bilkul saaf dikhne ke liye 10,000. Jo bhi kehta hai ki koi system isse kam spins mein kaam karta hai, woh noise report kar raha hai.
Formula
Sawaal
Pockets ki jagah sectorswheelSectorWheel par pockets ka lagatar ek hissa (arc), layout ke kisi group se alag cheez.Poora padhein → test karna madad karta hai, kyunki physical defect aksar ek arc par asar daalta hai aur signal pockets mein jud jaata hai. Yeh order of magnitude nahi badalta.
Haan, agar wheel head wahi hai aur uski servicing nahi hui. Yahi jaanna mushkil hissa hai.
Convention. Iska matlab hai ki bataye gaye size ka asli bias paanch mein chaar baar pakda jaayega.
Thodi hansi

Noise 1/√n ki tarah girta hai. Sabr usse bhi tez.
Sources
- Feller, W. An Introduction to Probability Theory and Its Applications, Vol. 1.
- Barnhart, R. T. Beating the Wheel.