Whether a game is blitz or standard depends on a formula that takes into account both the Start time and the Increment (Inc) value to get a sense of the total time a game might last. Here is the formula:
BLITZ if_and_only_if (Start + Inc*2/3) < 15
STANDARD otherwise
The following table shows the slowest blitz and fastest standard time controls, the dividing line if you will between the two types of matches. [Thanks to schwartzeer for the calculations. :) ]
| Slowest Blitz | Fastest Standard | ||
| Mins | Incr | Mins | Incr |
| 1 | 20 | 1 | 21 |
| 2 | 19 | 2 | 20 |
| 3 | 17 | 3 | 18 |
| 4 | 16 | 4 | 17 |
| 5 | 14 | 5 | 15 |
| 6 | 13 | 6 | 14 |
| 7 | 11 | 7 | 12 |
| 8 | 10 | 8 | 11 |
| 9 | 8 | 9 | 9 |
| 10 | 7 | 10 | 8 |
| 11 | 5 | 11 | 6 |
| 12 | 4 | 12 | 5 |
| 13 | 2 | 13 | 3 |
| 14 | 1 | 14 | 2 |
| 15 | 0 | ||
As you can see, not every game with more minutes to start is Standard and not every game with few minutes to start is Blitz.
See also: match