Split bet

Among the inside bets in roulette, the split deservedly holds an honourable second place after straight-up bets. A split covers two numbers at once (5.4% of the European wheel) and pays 17:1, which makes it a balanced choice between the extreme risk of a straight-up bet and the modest payouts of outside bets. In this article we break down every nuance of the split bet in online casinos.

What the Split bet is: mechanics and key parameters

In any roulette variant the split (Cheval in French) is a bet on two paired numbers, so you can fund it with a single chip. You can only place a split on adjacent numbers in the table’s number field (or on the racetrack, but that’s a separate topic) — to do it, click the line that separates the numbers you want.

Key parameters: chance, payout, expected value

The difference between a split bet across roulette variants comes only from the second zero (00) in the American version, while French roulette is fully identical to European in this respect.

No roulette strategy can beat the house edge: in the long run a player still loses money on split bets, and the American wheel almost doubles the speed of that loss — on $1,000 of turnover the average loss is $27 under European rules but a full $53 under American.

How to place a Split bet: instructions

A split bet covers two numbers that are neighbours on the number field:

• horizontally;
• vertically;
• 0 and an adjacent number — 1, 2 or 3.

In every case the chip goes on the line separating the two numbers joined by the split — just click it.

Online roulette: how the split looks in the interface

So you don’t miss while placing the bet, the numbers that will receive the bet highlight when you hover over the field. Hover over the line and wait until both of your chosen numbers light up — if everything is right, click confidently. Live roulette offers the same mechanic, but there you mustn’t dawdle: you get only 30–45 seconds to place bets.

Split with zero: special combinations

Because of where the zero sits on the field, it can be paired with any of the three numbers in the first row — as 0-1, 0-2 or 0-3. In American roulette, where there are two zeros, you can combine them into a split. Splits with zero are no different from splits with other numbers — same win chance, same payout.

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Every possible split bet: the full combination map

Since a split on non-adjacent numbers is impossible to place, European roulette has 60 such bets, including horizontal and vertical “neighbourings” plus splits with zero (0-1, 0-2, 0-3); American roulette also has a special 61st split — 0-00 — plus three splits with the “second” zero 00 and the first-row numbers.

Horizontal splits: numbers side by side in a row

The number section has 12 rows of 3 numbers each — horizontal splits mean the paired numbers must be in the same row. Each row gives two horizontal-split options — 24 in total:

• row 1 — 1-2, 2-3;
• row 2 — 4-5, 5-6;
• row 3 — 7-8, 8-9;
• row 4 — 10-11, 11-12;
• row 5 — 13-14, 14-15;
• row 6 — 16-17, 17-18;
• row 7 — 19-20, 20-21;
• row 8 — 22-23, 23-24;
• row 9 — 25-26, 26-27;
• row 10 — 28-29, 29-30;
• row 11 — 31-32, 32-33;
• row 12 — 34-35, 35-36.

All horizontal splits are equal in terms of win chance (5.4%) and payout (17:1).

Vertical splits: numbers in adjacent rows of one column

Vertical splits let you bet on two numbers from adjacent rows as long as one side fully abuts the other. There are 33 such splits in total — 11 in each of the three columns:

• left (first) — 1-4, 4-7, 7-10, 10-13, 13-16, 16-19, 19-22, 22-25, 25-28, 28-31, 31-34;
• middle (second) — 2-5, 5-8, 8-11, 11-14, 14-17, 17-20, 20-23, 23-26, 26-29, 29-32, 32-35;
• right (third) — 3-6, 6-9, 9-12, 12-15, 15-18, 18-21, 21-24, 24-27, 27-30, 30-33, 33-36.

Like the horizontal ones, all vertical splits are identical in win probability and payout (17:1).

The math of the split bet: probabilities, payouts and RTP

Although split bets bring a player no closer to profit (the RTP of most roulette bets is the same over the long run), it’s worth understanding the math behind the move to make an informed choice in its favour.

Calculating the probability: why 5.4%

Roulette math is such that the probability of any single number landing is the same: it’s 2/37 (5.4%) for European and French roulette, and 2/38 (5.26%) for American.

How the 17:1 payout works: real profit per spin

The payout on a winning split is 17:1 — that is, your stake is returned and 17× is added on top. Stake $1 and win, and you collect $18 ($17 net profit); lose, and you forfeit the stake. One split win covers 17 losses.

Why the payout is 17:1, not a fair 18:1: where the house edge comes from

At a 2/37 win chance, some players consider 37/2 a fair payout — but that’s 18.5:1, not 17. Real-money roulette, however, pays out rounded down, so the casino can pay winnings of any size on time and still earn on top. Since no player can win forever, and over a long run wins and losses tend toward the mathematical average, you still lose the 2.7% that keeps the RTP from being a round 97.3%.

Comparing the split with other inside bets

For casino visitors still new to online roulette, it helps to understand how the split differs from other inside bets.

All inside bets on European roulette share the same RTP, but variance differs — you can win rarely but big, often but small, or somewhere in between. The split is valued as less risky than a straight-up bet while still carrying a huge payout.

Split-bet test: 1,000 spins with real data

To assess split bets over the long run we used a Google Sheets algorithm with standard conditions: we simulated four players betting the same split 1,000 times each but with different stakes — $1, $2, $3 and $5. Each player’s starting bankroll was set at $1,000.

Test results: what 1,000 spins showed

The results let us see how variance and different stakes affect things:

• the first player, betting $1, ended in an insignificant minus roughly matching the average 2.7% house edge — and even that only happened near the end of the session, while in the first half he held a plus for a long time;
• the second player, betting $2, got lucky — he was in the plus for most of the session and finished there too, growing the bank by 18%;
• the third player ($3 stakes) saw a chance to double the bank in the first half but slid into the minus toward the end, then hovered near a 5% loss before being saved at the last moment, finishing roughly at break-even;
• the fourth player, with $5 stakes, held near zero for the first couple hundred spins, but then a drawdown hit and several times he had less than half his bank left.

You can test the split-bet strategy yourself in demo mode, but real roulette free and without registration would take 10–15 hours for 1,000 spins in a live version and at least 2–3 hours with an RNG. In practice players limit themselves to 50–200 spins, and even there results will differ. The actual outcome depends heavily on the moment a player decides to stop.

Why a smaller stake is safer: the math of drawdown

Although the test proves the influence of variance (some get luckier than others), a modest stake size still acts as a kind of insurance. The reason is simple: with 20 losses in a row at $1 a stake, the running minus is just $20, but if those were $5 stakes, the loss is already $100 — a small bank may not survive that. And a run of 20 losses in a row is far from a sensation in split bets: (35/37)^20 = 29.6%.

What the test does NOT show: limits of the simulation

Although our test was deliberately run from four players to show different session scenarios over 1,000 bets, a fifth test could have shown a record plus or, conversely, a minus. In split bets, where a win happens only roughly every 18 spins, much depends on whether an “extra” success fits into the session — or, conversely, whether even one “scheduled” payout gets missed. High variance means that at roulette’s standard RTP (97.3% for the European version) a stable convergence to the average happens even later than after 1,000 spins — the luck factor kicks in.

Strategies with split bets: from simple combinations to systems

The split can be used as the bet within one of the roulette strategies — for example, aiming to cover most of the wheel.

Strategy 1: Split + outside bet (hedging)

A vivid example of a split strategy is chasing a rare big payout and a small but very likely win at the same time. For example, bet $10 on black and $1 on the red split 16-19. With a total stake of $11 the scenarios are:

• black hits — 48.6% probability, +$9 to the bank;
• the split hits — 5.4% probability, +$7 to the bank;
• a loss — 46% probability, -$11.

The bets can partly overlap if the split touches the same colour with one or both numbers; then the overall win chance drops a little (fewer numbers covered in total), but there’s a scenario where both bets hit at once — that’s already +$17.

How to calculate the optimal stake ratio when hedging

The example above is for orientation; the ratio of stake sizes can differ. The math shows that when combining one split and one 1:1 bet, the split’s value should be only 5–10% of the outside bet, otherwise the latter won’t fulfil its protective function.

Strategy 2: 14 splits — covering 28 numbers

A popular roulette approach is aiming for a small but almost guaranteed plus. One option is placing 14 non-overlapping splits; this covers 28/37 of the wheel, giving a 75.7% win chance. Spending 14 chips, on a win we collect 17:1 — and come out +4 chips. At the same time the loss chance, though only 24.3%, means losing 14 chips at once, so the value of such a bet doesn’t change roulette’s RTP over the long run at all.

Which 14 splits to choose: one working configuration

Given the equal probability of every number landing, you can use any 14 splits as long as they don’t touch each other. A simple example of how to pick 14 splits: take all the horizontal “pairs” from the left edge in each of the 12 columns and add 2 vertical splits.

Strategy 3: 9 splits — covering 18 numbers

By placing 9 non-overlapping splits, a player essentially gets a 1:1-type bet — with a 48.6% win chance. Winning on any split, the player comes out +9 chips; losing, they go -9 chips. Variance can differ, though, especially if you play live roulette with a worn wheel, where the chance of the same adjacent numbers landing regularly is slightly higher. Progressive bankroll-management strategies add some spice, but Martingale (doubling the stake after a loss) looks too risky — better to use the more cautious D’Alembert (adding one unit after a failure).

Strategy 4: Finals à Cheval — splits with the same last digit

You can also pick splits by their last digits — for example, so the splits end in 3 and 6: 3-6, 13-16, 23-26, 33-36. This strategy can’t be used for all numbers, because splits 13-14 and 23-24 are available but 3-4 and 33-34 are not (they aren’t adjacent on the betting field). Also the fourth decade isn’t full (there are no numbers above 36), so Finals à Cheval splits sometimes mean four and sometimes three bets. That changes the bet’s figures too:

• three splits (three chips) — 16.2% win chance, +15 chips on a win;
• four splits (four chips) — 21.6% win chance, +14 chips on a win.

In practice you can just as well bet any three or four splits without tying them to last digits.

Strategy 5: splits on wheel sectors (via the racetrack)

When the roulette interface has a racetrack, you gain access to bets on pairs of numbers that aren’t adjacent on the betting field but are neighbours on the wheel; by that logic you could bet a split on 17-20, for example. In effect this lets you cover a certain sector of the wheel if you believe “hot” numbers sit somewhere within it. The scale of coverage (number of splits) is up to the player.

The Split bet in European, American and French roulette

In every roulette variant the split is a paired bet on two numbers, but the rule specifics of individual variants do shift the bet’s mathematical content somewhat. In the text we’ve mostly given the split’s parameters for European roulette, but an experienced player must understand the difference to avoid surprises.

Split in European roulette: 60 combinations, 5.40% chance

The European wheel has 37 numbers (1–36 and zero); the field lets you combine them into 60 splits, including three split options with zero. The win chance is 5.4%, and the bet’s RTP is 97.3%.

Split in American roulette: 64 combinations, 5.26% chance

American roulette has 38 cells thanks to two zeros (0 and 00) — the “extra” zero creates the splits 0-00, 00-1, 00-2 and 00-3 that don’t exist in other roulette variants. Because of the extra numbers the win chance drops slightly — to 5.26% — and the RTP is estimated at 94.74%. Experienced players usually don’t play American roulette when European or French is available — splits in the latter two are more favourable.

Split in French roulette: the racetrack factor

Visually French roulette looks much like European: 37 cells should supposedly give 60 splits, but in fact the presence of a racetrack means you can also bet a split on numbers that are neighbours only on the wheel (not placed side by side on the field). The win chance for a split in French roulette is still 5.4%, but although this variant is often praised for the highest RTP of 98.65%, that figure is provided by the La Partage and En Prison rules, which don’t apply to splits and other inside bets. Without those rules, the RTP on splits in French roulette equals the same figure as European roulette — 97.3%.

Who the Split bet suits: player profile and recommendations

Although the split is still a fairly high-risk bet (only a 5.4% win chance), it’s often called the golden mean: not the sky-high risk of a straight-up bet, but not the modest payout of outside bets either.

When to choose the split over a straight-up bet

The split is appropriate when a straight-up bet weighs on you psychologically with how rare wins are: if a one-number bet wins on average once in 37 spins, a split wins once in 18–19. For the same reason a split is worth choosing when the bank isn’t very big. And a split’s 17:1 payout (instead of 35:1 for a straight-up) can still bring vivid emotion on a win.

When to choose the split over outside bets

Outside bets attract many players with the regularity of wins, but people still come to the casino to take risks and enjoy big payouts — and from that angle the split is far more interesting. If you want to feel vivid emotion and long losing streaks don’t scare you, inside bets are worth a look — and to avoid overdoing the risk, the split is better than straight-up bets.

Selection table: which bet suits your style

If you’re new to roulette, the table below will help you understand which bets suit you.

So, the split shows its best in the balance of risk and reasonably large payouts.