2/3 Roulette System
The 2/3 Roulette System watches 28 spins, then covers 16 unhit numbers with straight-up chips. A record of past spins cannot make those numbers more likely on the next spin.
The stated rule only produces exactly 16 unhit numbers when 21 distinct pockets have appeared. With a fixed 16-chip layout, a hit nets +20 and a miss −16, for an expected lossmathExpected lossExpected value times total amount wagered; the average amount lost over a session or a period.Read full → of 16/37 units per wager.
The stated observation rule
Record 28 European-wheel results. The circulating trigger requires a repeated number among spins 26–28 and at most 21 distinct pocketsequipmentPocketOne of the 37 numbered compartments on the rotor. Also: slot, cup.Read full → in the full record. This analysis restricts the layoutequipmentLayoutThe printed betting grid on the table. Also: table, felt, cloth.Read full → to exactly 21 distinct pockets because the rule leaves the below-21 case unspecified. With exactly 21 distinct pockets seen, 16 of the 37 pockets remain unhit, so place one straight-up chipmoneyChipA token representing a fixed amount, placed on the layout to make a bet. Also: check.Read full → on each of those 16 numbers for the next spin. The observation identifies a layout; it does not predict the next pocket.
An important unresolved case
Fewer than 21 distinct pockets leave more than 16 numbers unhit. The rule does not say which unhit numbers to omit, so that case is an unspecified selection, not permission to silently choose any 16. This analysis therefore evaluates the only fully specified layout: exactly 16 one-chip straight-up bets.
Fixed 16-number payout table
The 16 chips are all live on every wager. A straight-up win returns 36 times its chip including the chip itself, while the other 15 chips lose.
Worked example
Suppose the record contains exactly 21 distinct pockets and 7 repeats, with one repeat in spins 26–28. The complement is then a definite 16-number set. If the next spin is one of those 16, its one-unitmoneyUnitThe base stake a system or a player works in. Progressions are described in units so they apply at any table.Read full → straight-up return is 36 and the net after all 16 chips is +20. If it is any of the other 21 pockets, no chip returns and the result is −16. The preceding record does not alter the 16/37 and 21/37 probabilities.
Distinct pockets are not a hard limit
After 37 independent European-wheel spins, the expected number of distinct pockets is 23.5745. That average is not a ceiling: the chance of seeing more than 24 distinct pockets is 31.2839%. An occupancy average describes many samples; it does not impose a maximum on a particular record or make later spins compensate for earlier repeats.
Risk and expectation
For the fixed layout, expected net is (16 × 20 − 21 × 16) / 37 = −16/37 units per wager. That is the usual European 2.70% loss applied to 16 units of turnovermoneyTurnoverThe total amount wagered over a session or period, counting re-bet winnings. Also: handle, action.Read full →. The layout can make a +20 result more frequent than a single straight-up hit, but it also risks 16 units whenever none of its selected numbers lands. Cold-number selection changes neither coverage nor expected valuemathExpected valueThe average result per bet over the long run. −1/37 of the stake for every standard European bet.Read full →.
Questions
No. Each next European-wheel spin still gives each individual pocket probabilitymathProbabilityChance of an outcome, from 0 to 1 or 0% to 100%. One number: 1/37 = 2.70%.Read full → 1/37. An unhit number has no accumulated claim on the next result.
The stated rule does not specify which of the more than 16 unhit numbers to exclude. A complete rule must state that choice before it can be analysed as a fixed layout.
Sources
- RouletteDoc, Strategy overview
- Roulette77, Strategy overview