The screen flashes 確変, the music changes, the balls suddenly flow into the start pocket, and everyone nearby seems to know what that means. Here’s what those modes are, in plain English, using the makers’ own definitions.
The building blocks
| Term | Japanese | Plain-English meaning | Official source |
|---|---|---|---|
| Kakuhen | 確変 (確率変動) | A mode with raised jackpot probability. Usually comes with electric support | SANKYO Q&A 2 |
| Electric support | 電サポ (densapo) | The start pocket opens wider or more often, so you lose fewer balls between spins | SANKYO Q&A 2, Q&A 41 |
| ST | ST (スペシャルタイム) | Special Time: a kakuhen that lasts a fixed number of spins | SANKYO Q&A 6 |
| Jitan | 時短 | “Time-saving”: normal odds plus electric support | SANKYO Q&A 41 |
| Yu-time | 遊タイム | Jitan that starts after a set number of normal spins without a jackpot. Not a guaranteed hit | SANKYO Q&A 36 |
| RUSH | ラッシュ | Marketing name many machines use for their bonus mode (kakuhen, ST or jitan) | Machine-specific |
Japanese Wikipedia dates the introduction of kakuhen to 1990 (ja.wikipedia, secondary source).
How a typical cycle looks
- Normal play (通常時). You shoot balls, some enter the start pocket, and each one triggers a spin at the normal odds, for example about 1/319 on a middle machine (machine types).
- Jackpot (大当たり). The attacker gate opens for a set number of rounds and pays balls.
- What comes next depends on the machine:
- Kakuhen. Raised odds with support, often lasting until the next jackpot (a “loop” machine).
- ST. Raised odds for a fixed number of spins only.
- Jitan. Normal odds, but fast, cheap spins for a set number of turns.
- Back to normal play.
A real example
SANKYO’s official walkthrough of P Fever Powerful shows how these pieces combine (SANKYO):
| Item | Value on the spec sheet |
|---|---|
| Normal odds → kakuhen odds | 1/99.9 → 1/12.0 |
| ST length | 8 spins |
| Electric support after a jackpot | 25, 50 or 100 spins (including the 8 ST spins; the rest is jitan) |
| Kakuhen entry | 100% |
| Overall continuation (SANKYO’s figure) | about 65.0% |
| Yu-time | Jitan for 100 spins after 292 spins in normal play without a jackpot |
So on this machine every jackpot gives a short ST, followed by jitan. SANKYO’s “about 65%” figure is the chance of chaining into another jackpot during that support period. It’s a long-run design value, not a promise for any one session.
Types of kakuhen you’ll hear about
A Japanese pachinko glossary groups kakuhen into four broad styles (ppps.jp):
- Loop (ループ): kakuhen continues until the next jackpot.
- ST: kakuhen for a fixed number of spins.
- Fall-out (転落): each spin has a small chance of dropping out of kakuhen.
- Hidden (潜伏): the machine is in kakuhen but doesn’t show it.
The same glossary notes that some 2026 machines label their mode “ST=時短”. Under newer specs, part of what players call ST may technically be jitan. Read the machine’s own spec panel rather than assuming (ppps.jp).
Yu-time: a rescue feature, not a target
Yu-time appeared after an industry rule change at the end of 2019. DMM’s history names P Fever Shin Kagetsu 2 Yozakura as the first machine to carry it (DMM, Japanese). SANKYO’s Q&A explains that since April 2022 the trigger point must sit between 1.5× and just under 3× the jackpot odds denominator, and that yu-time doesn’t guarantee a jackpot (SANKYO Q&A 36).
We deliberately don’t publish “aim for machines near yu-time” advice. You’ll find that elsewhere, but it encourages chasing, and it doesn’t change the long-run design of the machine.
Spotting the mode on screen
| On screen | Likely meaning |
|---|---|
| 確変 / 確率変動中 | Kakuhen active |
| ST / ST中 残り○回 | ST active, with spins remaining |
| 時短 / 電サポ中 | Jitan or electric support |
| 右打ち (migi-uchi) | Shoot right: turn the handle fully so balls go down the right side. Staff will happily show you |
| 左打ちに戻してください | Return to shooting left (mode has ended) |
| 遊タイム突入 | Yu-time has started |
Japanese screen words are collected in Pachinko Japanese: phrases and screen words, and short definitions are in the glossary.
Quick answers
What does kakuhen mean in pachinko?
Kakuhen (確変, short for 確率変動, 'probability change') is a bonus mode where the jackpot probability is raised above normal. It usually comes with 'electric support', which makes balls easier to get into the start pocket, so you lose fewer balls between spins.
What is ST in pachinko?
ST means 'Special Time'. It's a kakuhen that lasts a fixed number of spins. If the next jackpot doesn't arrive within those spins, the machine drops back to normal play.
What is jitan?
Jitan (時短, 'time-saving') keeps the normal jackpot odds but turns on electric support, so spins come quickly and cheaply. It often follows a non-kakuhen jackpot or the end of an ST.
Does yu-time guarantee a jackpot?
No. Yu-time (遊タイム) gives a period of jitan after a set number of spins in normal play without a jackpot. SANKYO's official Q&A states that it doesn't guarantee a hit.
Can I tell if a machine is in kakuhen?
The screen and lamps usually tell you during an obvious bonus mode. Some machines also have hidden (潜伏) kakuhen that isn't shown, which is part of the design. Don't try to guess hidden states. Treat each spin as independent.
Sources
- SANKYO official Q&A – kakuhen (raised probability, usually with 電サポ)
- SANKYO official Q&A – ST (Special Time)
- SANKYO official Q&A – jitan (normal odds with 電サポ)
- SANKYO official Q&A – yu-time (trigger 1.5× to under 3× the odds since April 2022; not guaranteed)
- SANKYO – how to read a spec sheet (P Fever Powerful example)
- ppps.jp – kakuhen types: loop, ST, 転落, 潜伏; 'ST=時短' labelling (Japanese)
- DMM Pachitown – yu-time history (Japanese)
- ja.wikipedia – Pachinko (kakuhen introduced 1990; secondary source)
Facts on this page were last checked against these sources on 4 October 2026. Rules, prices and venues change, so always follow the signs and staff at the venue.
