Cost of Errors when Shuffle Tracking

This page contains a series of Blackjack Shuffle Tracking simulations to get a sense of the cost of making errors. The Blackjack rules are a fairly standard 4.5/6, S17, DAS. For this study I wanted to work with a simple shuffle and procedure. So, I used a simple one pass rifle & restack with four grabs from each stack. (Yes this shuffle still exists, albeit rarely.) The Trackzone is the bottom 39 cards. A bad slug is cut out of play and a good slug is cut one deck from the top. A spread of 1:15 was used, HiLo was the counting system with 20 accurate indices, and NRS was used for playing and betting through the play zones. The dealer accuracy in performing the shuffle was set to typical riffle accuracy and a fairly tight plus or minus 8 cards on the split and plus or minus 3 cards on the grabs. Only one track zone was used. Every shuffle was cut according to track zone content.

The Sims

Eleven sims were performed as follows:

• I. Standard card counting, no shuffle tracking.
• II. Extended NRS used with a multiplier of -1.4 and an adjustment of .2. (This is the extended NRS adjustment used to take into account the count of the cards before the play zone starts and is typically not used by shuffle trackers.)
• III. Standard NRS used with a compromise -1.5 multiplier and no adjustment. (This is the benchmark. All further sims were run in this manner.)
• IV. Play zone +6. That is, the play zone starts 6 cards late.
• V. Cut +6. That is, the cut is made 6 cards too deeply.
• VI. Cut -6.
• VII. Play zone length +12. That is, ending the play zone 12 cards late. Note: I generally set the PZ length about 6 cards short to avoid zone edge problems. Thus, +12 is not as far off as it sounds. Although a few STers seek to make use of the count differences at zone edges, I believe most do not.
• VIII. Track zone -6. That is, the TZ is 6 cards short.
• IX. Track zone +6
• X. Combination of Cut +6 and PZ +6.
• XI. No Play zone at all with a good slug. The bad slugs are still cut out of play.

The Chart

Below you will see the SCORE for each sim:

Comments

• 1. First the obvious. At least with this simple scenario, shuffle tracking can be very profitable. However, be warned that this is hardly a common shuffle these days.
• 2. An improvement from standard NRS to extended NRS exists, but is not great. However, had I cut the good slugs further into the shoe the gain from extended NRS would have been greater.
• 3. Generally speaking, the overall cost of errors was not that bad. However, it should be noted that this is hardly a comprehensive study as only one shuffle was included. A smaller track zone, or a more diluted play zone would be likely to experience much greater error effects.
• 4. In this series, an error in the track zone length was more severe than errors in locating the play zone. This is good news as TZ location is generally the easier task.
• 5. Combinations of errors can have a much greater impact than single errors. This is hardly surprising as multiple errors can multiply the effect.
• 6. Comparing sims II, X and XI we see that nearly all of the gain of cutting good cards into play can be lost by two errors.
• 7. Even with no attempt at cutting good cards into play, the SCORE was dramatically improved. This is great news as cutting bad cards out of play is vastly easier than cutting good cards into play and using NRS methodology to bet through the play zone. In fact, a lone player that cannot simultaneously keep track of both a play zone and track zone in one shuffle might be better off only cutting bad cards out of play instead of tracking every other shuffle.

Caveat

Again, this is hardly a comprehensive study. There are a huge number of variables in standard Blackjack card counting simulations. This is multiplied considerably in shuffle tracking sims. For the purposes of this sim, only one shuffle and one method of attacking the shuffle were used. Further, only one fairly tight dealer was used.