Decode BB, RB, total games and the graph above a Japanese slot machine. Worked examples show how to calculate observed rates and avoid misleading comparisons.
How to Read a Pachislot Data Counter: BB, RB and Games
What the Japanese labels usually mean
A data counter reports recorded play history. It is separate from the cabinet’s credit display and the cash/card unit. Display models and hall configurations differ, so treat these as common meanings and check the explanation for the installed counter.
| Label | Meaning to check |
|---|---|
| BB / BIG | Recorded big-bonus events; on AT machines, the mapping may represent a different event. |
| RB / REG | Recorded regular-bonus events; do not assume it means the same event across models. |
| 総回転 / 累計ゲーム | Total recorded games for the selected period. |
| スタート / 現在ゲーム | Games since the counter’s configured reset event. |
| 合算 | A combined event rate, calculated from the events and games included by that counter. |
| 差枚 / スランプグラフ | Net-medal information or a graph; check the unit, period and definition. |
| 本日 / 前日 / 2日前 | Today / yesterday / two days ago. |
SANKYO describes data lamps as a way to check information such as bonus counts. The table above translates common labels; it is not a specification for every counter.
Worked example: calculate BB, RB and combined rates
Imagine a bonus-focused machine showing 3,000 relevant games, 12 BB and 10 RB. Assume the game denominator matches the probability table you are comparing with. These are invented numbers for arithmetic, not a high-setting recommendation.
| Measure | Calculation | Result |
|---|---|---|
| BB | 3,000 ÷ 12 | 1 in 250 games |
| RB | 3,000 ÷ 10 | 1 in 300 games |
| BB + RB | 3,000 ÷ (12 + 10) | About 1 in 136.4 games |
The combined rate is calculated from the combined count. Averaging the two denominators, (250 + 300) ÷ 2 = 275, is incorrect. If the event count is zero, report “0 events in 3,000 games”; dividing by zero does not produce a usable observed denominator.
If your counter includes bonus games in its total but a published probability uses ordinary games only, this calculation is not directly comparable. Confirm the counting convention before comparing the numbers with the exact machine profile.
Does a good RB rate prove setting 6?
No. An observed rate is what happened in one sample. A machine’s setting changes particular probabilities according to that model’s specification. Several settings can produce similar short-session results, and the same setting can produce very different sessions.
For a simple independent-event illustration with a fixed probability of 1/300, 3,000 games have an expected count of 10 events. The standard deviation of the count is about 3.16, calculated as √(3,000 × 1/300 × 299/300). That is a measure of variation, not a promise to finish at 10 or within any particular interval.
This model is appropriate only when its fixed-probability and independence assumptions fit the event being counted. AT entries, zones and state-dependent sequences should not automatically be treated as independent trials with a single constant probability.
Keep BB and RB separate when the machine’s setting differences differ between them. Even then, rates alone do not reveal the true setting. Read the setting-specific explanations and payout-rate definition before drawing conclusions.
Is the displayed game count the ceiling counter?
Not necessarily. The external counter can reset after an event that does not reset the machine’s internal ceiling counter. A machine may count points, cycles or games between particular events. A bonus-only ceiling also does not promise an AT entry.
For example, seeing “400” on a display is insufficient to subtract 400 from a published “1,000-game ceiling.” First establish what both figures count, the current reset conditions and any extra interval. Our machine pages separate the ceiling condition, awarded result, AT-interval status and budget assumptions.
What a rising or falling graph cannot tell you
A graph describes the selected history. It does not show an obligation for the next player to win, and a falling line does not mean a machine is “due.” A positive net-medal figure is also not automatically your personal cash profit: the chart may include earlier players, while lending and prize values can differ.
Before using a graph, check the selected day, vertical unit, zero point and whether the figure is net medals or gross output. Compare your own start and finish records only after confirming they measure the same thing.
A practical reading order
- Confirm the machine name and selected day.
- Read total games and the current-game count separately.
- Confirm which events BB and RB represent.
- Calculate each observed rate with the matching denominator.
- Check the exact machine’s setting and ceiling explanations.
- Use the information within your existing spending limit.
For payment and cash balances, continue to pachislot costs and credits. For the full visit, use the beginner guide.
Sources and editorial notes
Written by Japanese Slot Guide. Reviewed September 5, 2026. Calculations and worked examples are our own illustrations; they are not records from a real machine or promises of results.
- SANKYO: Machine selection and data lamps (Japanese)
- MARUHAN: Official machine-data app and available history (Japanese)
For our verification approach, see Editorial Policy & Data Sources. For limits and support, see Responsible Play.