Six Line
Two adjacent rows, six numbers, one chip.

Six numbers, pays 5:1. ProbabilitymathProbabilityChance of an outcome, from 0 to 1 or 0% to 100%. One number: 1/37 = 2.70%.Read full → 16.22%.
Placement
ChipmoneyChipA token representing a fixed amount, placed on the layout to make a bet. Also: check.Read full → on the outer edge of the grid at the line between two rows, covering both: 16-17-18 and 19-20-21, for example. There are eleven six-lines (1–6 through 31–36). No six-line includes zerowheelZeroThe single green pocket that no even-money, dozen or column bet covers; the source of the house edge. Also: single zero, 0.Read full →. The chip must sit on the intersection of the row line and the grid edge; on the row line only it is a streetbetStreetThree numbers in a row of the layout, pays 11:1. French: transversale.Read full →.
Payout and expectation
Fair odds are 5.17 to 1; the table pays 5. A $10 six-line that hits returns $50. Over 37 average spins: six hits (+$300), 31 misses (−$310), net −$10.
Character
The largest inside betbetInside betAny bet placed on or between the numbers of the grid: straight up, split, street, corner, six line.Read full → and the bridge to the outside: half a dozen in coverage, at the matching payoutmoneyPayoutWhat a winning bet returns, quoted as “X to 1” on top of the returned stake.Read full →. Hits come about every six spins, and a 100-spin session almost never goes without one. The six-line is also the five-chip component of the James Bond spread, which puts five unitsmoneyUnitThe base stake a system or a player works in. Progressions are described in units so they apply at any table.Read full → on 13–18.
Six lines and dozens
Two six-lines make a dozenbetDozen1–12, 13–24 or 25–36, pays 2:1.Read full → (1–6 plus 7–12 covers 1–12). Two $10 six-lines pay $50 − $10 = $40 when the dozen hits; a $20 dozen pays $40. Same bet, two shapes. Six-lines earn their place when you want to weight half a dozen or straddle two dozens, such as 10–15.
Names
SixainFR · six lineSixainFrench for six line: six numbers in two rows, pays 5:1.Read full → or transversaleFR · streetTransversaleFrench for street (transversale pleine, 3 numbers) and six line (transversale simple, 6 numbers).Read full → simple in French; “line bet”, “double street” or “six-number bet” in English; sometimes “sixline” as one word on live interfaces.
Questions
No. Zero is a single cell at the head of the layoutequipmentLayoutThe printed betting grid on the table. Also: table, felt, cloth.Read full → and forms streets (0-1-2, 0-2-3) and the basketbetBasketOn a single-zero wheel: 0, 1, 2, 3 with one chip, pays 8:1. Also: first four, quatre premiers.Read full →, not a six-line.
√(p·25 + (1−p) − EV²) with p = 6/37. Lower than any other inside bet.
Comic relief

The largest inside bet, and the last one before the outside.
Sources
- Ethier, S. N. The Doctrine of Chances: Probabilistic Aspects of Gambling.