Short answer: 10/5 means each player starts with 10 minutes on the clock and gets 5 extra seconds added back after every move they make. The first number is your base time in minutes, the second is the increment in seconds. That is the whole idea. Below we break it down, show you why the slash sometimes looks like a plus or a bar, and decode the other common time controls you will run into.
The Quick Answer
Every chess time control is written the same way: base time then increment. Once you know that, you can read any of them.
Reading "10/5"
So you begin with 10 minutes, and every time you move you earn 5 seconds. Play a 40 move game and you have banked an extra 3 minutes 20 seconds along the way. If your clock ever hits zero, you lose, even in a winning position.
Slash, Pipe or Plus: Same Thing
Here is what trips people up. The same time control gets written three different ways depending on where you see it, and they all mean exactly the same thing:
- 10/5 - the slash form, common in casual chat and some apps.
- 10 | 5 - the pipe form, used on Chess.com and other online sites.
- 10+5 - the plus form, standard for over-the-board and FIDE events.
Do not overthink it. Whether you see a slash, a bar or a plus, read it as minutes then increment seconds. There is no hidden difference in the symbol.
A single number with no second value, like "5" or "3", means no increment at all. So 5/0 and plain "5 minute" are the same: 5 minutes each, nothing added per move.
Common Controls Decoded
Here are the time controls you will meet most often, translated into plain English. The categories use the widely used FIDE-aligned bands based on each player's total time.
| Written As | Base | Increment | Category | Typical Use |
|---|---|---|---|---|
| 1/0 | 1 min | None | Bullet | Frantic online games |
| 3/2 | 3 min | 2 sec | Blitz | Popular online blitz |
| 5/0 | 5 min | None | Blitz | Classic pub / casual blitz |
| 10/5 | 10 min | 5 sec | Rapid (light) | Club nights, friendly events |
| 15/10 | 15 min | 10 sec | Rapid | Serious one-evening events |
| 25/0 | 25 min | None | Rapid | School and quick rated play |
| 90/30 | 90 min | 30 sec | Classical | Weekend opens, rated events |
Is 10/5 Blitz or Rapid?
This one confuses even regular players. The dividing line between blitz and rapid usually sits at 10 minutes of base time, so 10/5 lands right on the boundary. Because of the 5 second increment, though, you actually get noticeably more than 10 minutes across a full game, so 10/5 plays and is generally classed as a light rapid control. In practice it is a lovely middle ground: fast enough to fit several rounds into a night, slow enough that players are not just flinging pieces.
Increment vs Delay
There are two ways time can be added per move, and they are not quite the same:
- Increment (Fischer): the bonus seconds are added to your clock after every move and they accumulate. This is what 10/5 means.
- Delay (Bronstein / US delay): your clock pauses for a few seconds before it starts counting down, but any unused delay does not bank. Often written as 10 d5.
Both exist to stop a player being flagged in a clearly winning position. Increment is the more common of the two online and in most modern events.
Why It Matters for Organizers
If you are running the event rather than just playing in it, the time control is your single biggest scheduling lever. The worst-case length of one game is roughly twice the base time plus increment across the moves, and that number decides how many rounds you can fit in a session.
Example: Planning a Club Night at 10/5
Bump up to 15/10 and rounds stretch to around 45 minutes, so you fit fewer of them. Our free tournament duration calculator does this maths for you.
Want to try the notation hands-on? Our free online chess clock lets you set any time control, including 10/5, and play with it right in your browser, no signup. And if you want the full picture on bullet, blitz, rapid and classical, read our complete guide to chess time controls.
Your time control decides how many rounds fit in your session. ChessHost, our free chess tournament organizer, sets up rounds and generates pairings in seconds, so once you have picked a clock you can run the whole event smoothly.
Frequently Asked Questions
What does 10/5 mean in chess?
Each player starts with 10 minutes and gains 5 seconds after every move. The first number is the base time in minutes, the second is the increment in seconds added back each move.
Is 10/5 the same as 10+5?
Yes. 10/5, 10+5 and 10 | 5 all describe the same control: 10 minutes base plus a 5 second increment per move. The slash, plus and pipe are just different ways of writing it.
What is the difference between the slash and the plus in chess notation?
None in meaning. Online sites often use a slash or pipe like 10/5 or 10 | 5, while over-the-board and FIDE events write a plus like 10+5. All of them mean base minutes plus increment seconds.
What does 3/2 mean in chess?
3/2 means 3 minutes each plus 2 seconds added after every move. It is a popular blitz control that stays fast while giving just enough increment to avoid flagging in a winning position.
Is 10/5 blitz or rapid?
It sits right on the line. The 10 minute base is the usual blitz-rapid boundary, but the 5 second increment gives extra time across a game, so 10/5 usually plays and is classed as a light rapid control.
Know Your Clock? Now Run the Event
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