The Fab 4: Surrender Deviations for Counters

Don Schlesinger's most quoted contribution to blackjack is the Illustrious 18, the ranked list of playing deviations that carry most of the count's value. His second most quoted is smaller, stranger, and in the right game arguably a better deal: four surrender indices, collectively the Fab 4, that a counter can learn in an afternoon.

Their claim to attention is a specific published finding. Where late surrender is offered, the Fab 4 are worth more than Illustrious 18 entries ten through eighteen combined. Four numbers outperforming nine is the kind of ratio that decides what a busy person memorizes.

The prerequisite nobody can work around

Every word that follows assumes your table offers late surrender: the option to abandon a hand after the deal, forfeiting half your bet, before drawing. Plenty of tables do not offer it, and at those tables the Fab 4 are worth precisely zero. There is no clever workaround. Check the rules first, exactly as our guide to surrender strategy recommends, because this entire skill lives or dies on one line of the house rules.

The second prerequisite is the count itself. These are true count numbers, so they need a maintained running count converted properly, the process our conversion guide covers. An index applied to a guess is not a deviation, it is a hunch with a decimal point.

The four numbers

Read the pattern rather than the rows and the list gets much easier to hold. Three of the four are a hard 15, ordered by how dangerous the dealer's card is: against a ten you give up at a neutral shoe, against an ace you need a slightly positive one, against a nine you need more positive still. The fourth extends the idea to a 14, which needs a genuinely ten-rich shoe before surrender beats playing it out.

These are the canonical numbers for common multi-deck games, and like all indices they shift with deck count, with the soft 17 rule, and with the counting system. A KO or Omega II player uses that system's own published indices; borrowing Hi-Lo's is not an approximation, it is an error.

21 Trainer ProDeviation training with surrender enabled, so the Fab 4 spots arrive live with the count running. Get the app

Which direction each index points

Here is the subtlety that trips up most people learning these, and it is worth slowing down for. An index is a threshold, not an instruction to surrender more: at or above the number you surrender, and below it you revert to the correct basic strategy play for that hand at that table.

For 14 against 10, 15 against 9 and 15 against an ace in a stand-on-soft-17 game, basic strategy does not surrender at all, so the index unlocks a play you would otherwise never make. Those are additions. But 15 against 10 is already a basic strategy surrender in that same game, which means its index of 0 works the other way: it tells you when the shoe has gone poor enough in tens that you should stop surrendering and hit instead.

That asymmetry is the honest character of deviations generally. The count does not simply make you more aggressive or more cautious; it tells you when a borderline decision has tipped, and borderline decisions tip in both directions.

Why four small numbers pay so well

Two reasons, and both are structural rather than lucky. The first is frequency: hard 14s and 15s against big dealer cards are common. Fifteen against a ten in particular is one of the most frequently dealt bad spots in blackjack, so a rule that improves it slightly gets applied constantly, and small edges applied often add up faster than large edges applied rarely.

The second is that surrender is a cheap, precise instrument. Most deviations shift you between two live options, hitting or standing, where the gain is a sliver of a bad situation. Surrender caps the loss at exactly half a bet, which makes it the ideal tool for hands that are losing badly, and a ten-rich shoe is precisely when the game's worst hands get worse. The count and the tool point the same direction.

By contrast the tail of the Illustrious 18, entries ten through eighteen, covers spots that arise less often and move expectation less when they do. Learning nine of those is real work for a modest return, which is exactly why Schlesinger's ranking exists: it tells you where to stop.

Where they sit in the learning order

Last, along with all other index plays. The order that works, laid out in our counting overview, is automatic basic strategy, then a reliable running count, then true count conversion, then a bet spread, and only then deviations, starting with insurance at +3 and continuing down the ranking. If surrender is available in the games you play, the Fab 4 slot in immediately after insurance and ahead of most of the Illustrious 18.

Practicing them has one specific requirement: the spots have to arrive with a live count attached, because recognizing "15 against a ten at true +1" is a different skill from reciting the table. That is what a deviation trainer is for. In 21 Trainer, enable late surrender in the rules, run the deviation drill, and the four situations appear inside normal play with the count running underneath, which is the only realistic way to convert a small table of numbers into something you can actually execute at speed.

And keep the honest frame from the rest of this cluster: the Fab 4 refine a thin edge inside a game with heavy variance, at tables that may not offer surrender at all, played by casinos entitled to refuse service to counters. They are a beautifully economical piece of applied math. That, not a promise about outcomes, is the reason to learn them.