Earlier posts in this series cover how a running count becomes a true count, why penetration limits what the count can show, and how the Illustrious 18 change playing decisions. This one covers the other use of the count: setting the bet size. It is written to explain how the technique works. It is not a recommendation to play for money.
The rule of thumb
A widely quoted approximation says that each +1 of Hi-Lo true count shifts the player's expectation by about 0.5 percentage points. It is a rule of thumb, not an exact law: the true figure depends on the rules, the number of decks and how the count is converted. For a six-deck game with fairly friendly rules, the base house edge with correct basic strategy is also about 0.5%. Putting the two together gives a simple line:
player edge ≈ −0.5% + 0.5% × true count
Break-even is where that equals zero: −0.5 + 0.5 × TC = 0, so TC = +1. Below +1 the house is ahead. At +1 the game is roughly level. Above it the player is the one with the edge, and the edge grows by about half a point for each further step.
An illustrative 1 to 8 unit ramp
A bet ramp is a table that turns the true count into a bet. This one is made up to show the shape, not taken from any source. A “unit” is just the smallest bet, whatever size that is.
| True count | Approx. edge | Bet (units) | Expected result per round |
|---|---|---|---|
| 0 or below | −0.5% or worse | 1 | −0.005 units or worse |
| +1 | 0.0% | 1 | 0.000 |
| +2 | +0.5% | 2 | +0.010 |
| +3 | +1.0% | 4 | +0.040 |
| +4 | +1.5% | 6 | +0.090 |
| +5 or more | +2.0% or more | 8 | +0.160 or more |
The last column is edge multiplied by bet. At +3 that is 1.0% of 4 units, which is 0.04 units. At +5 it is 2.0% of 8 units, which is 0.16 units. A flat one-unit bet at +5 would be worth 0.02 units, so the ramp makes that round eight times as valuable, because the bet is eight times as large while the edge is the same.
Why the spread is needed
The gap between the smallest and largest bet is the spread, and here it is 1 to 8. The reason it matters is that the count is not positive very often. After a shuffle it starts at zero, and the early rounds sit near zero. At zero the player is behind by about 0.5%. A flat bet loses that 0.5% on every round at a neutral count, and gains only the same small amounts when the count is high.
The ramp changes the weighting. It keeps the bet small when the edge is negative or level, and puts more on the table when the edge is positive. The ramp does not change the cards. It changes how much each kind of round counts towards the total. A narrower spread, such as 1 to 2, would earn far less from the same counts, because the top bet is only twice the base even when the edge is large.
Why the tidy figures are only approximate
- The 0.5% per point is an average. It changes a little with the rule set and how many decks are in play.
- The base edge changes with the rules. A 6:5 natural, as explained in the house edge post, moves the break-even count well above +1.
- The true count is an estimate. Decks remaining are usually judged to the nearest half deck, and small slips matter more late in the shoe.
- An edge is not a result. A +1.0% edge at TC +3 means 0.01 of a bet per round on average. Single rounds swing by whole bets, so results over a short session can sit far from the average.
Practical limits in casinos
Tables set minimum and maximum bets, which caps the spread: a table with a narrow range cannot support 1 to 8 at a useful size. Penetration, covered in the earlier post, decides how often high true counts ever appear. Casinos are private businesses and can change their approach when they notice large bet changes that line up with the shoe, for example by shuffling earlier or asking a player to stop. None of this means the arithmetic is wrong. It means the arithmetic is the easy part, and a real table adds limits the formula ignores. Treat the ramp as a way to see why a count has value, not as a plan.
Edge ≈ −0.5% + 0.5% × TC is a rule of thumb. It puts break-even at TC +1, and a ramp from 1 to 8 units follows it up: 4 units at +3 (about +1.0%) and 8 units at +5 (about +2.0%).
Practising the count
The ramp only works if the true count is right, and that comes from drilling the basics: card values, the running total and the division by decks left. Blackjack Coach includes Hi-Lo card counting practice alongside hand values, basic strategy and insurance, so you can run a count and convert it. It is practice only: the app has no real-money gambling or prizes, and nothing in this post suggests a bet has any value outside the app. Its chart teaches fixed six-deck rules.
Blackjack Coach: Learn 21 includes Hi-Lo card counting practice alongside hand values, basic strategy and insurance. You choose a play, read the explanation and review your mistakes, and the chart teaches fixed six-deck rules. It is a learning app with no real-money gambling and no prizes, and practice does not guarantee gambling success.