Rapid ratings cover a very wide range of time controls and bump up
against regular (where games are dual rated)
It is perhaps worth spelling these out for those outside the US who are unfamiliar with USCF time controls. According to the USCF's Official Rules of Chess (thanks, DM, for the link!):
5C. Ratable time controls.
There are three rating systems: Regular (slow), Quick (fast) and
Blitz. For the purposes of rating G/minutes and inc/seconds (or
d/seconds), add minutes (mm) and seconds (ss) for total playing time
for each player. That is, total time equals minutes plus (seconds
times 60) or mm+ss; e.g.: G/60 d/5 = 60+5 = 65 minutes total playing
time for each player. Multiple time controls add all mm for each
control: mm = mm(1) + mm(2) + . . . .
Regular only: Total playing time for each player is greater than 65 minutes (mm+ss > 65).
Dual (both regular and quick): Total playing time for each player is from 30 to 65 minutes (30 < mm+ss <65).
Quick only: Total playing time for each player is more than 10 and less than 30 minutes (10 < mm+ss < 30)
For Regular, Dual and Quick the primary time (mm in minutes) must be
at least 5 minutes.
Blitz: Total playing time for each player is from 5 to 10 minutes
inclusive and the primary time control must be at least 3 minutes. 5 <
mm+ss < 10 All rounds must use the same time control.
USCF used to have a rapid range of G10 to G30. What these latest limits do is to bring them much closer to the FIDE time controls. According to the FIDE Laws of Chess:
Appendix A. Rapid chess
A.1 A ‘Rapid chess’ game is one where either all the moves must be
completed in a fixed time of more than 10 minutes but less than 60
minutes for each player; or the time allotted plus 60 times any
increment is of more than 10 minutes but less than 60 minutes for each
The advantage of the USCF system is that there are no gaps whereas for FIDE there can be gaps according to the ratings of the players. According to FIDE Rating Regulations effective from 1 July 2017:
1. Rate of Play
1.1 For a game to be rated each player must have the following minimum periods in which to complete all the moves, assuming the game lasts 60
Where at least one of the players in the game has a rating 2200 or
higher, each player must have a minimum of 120 minutes.
Where at least one of the players in the game has a rating 1600 or
higher, each player must have a minimum of 90 minutes.
Where both of the players in the game are rated below 1600, each
player must have a minimum of 60 minutes.
So if at least one player is rated 2200 or higher time controls between G61 and G119 are not eligible for any rating.
If at least one player is rated 1600 or higher time controls between G61 and G89 are not eligible for any rating.
Comments on the validity of the extremes are also welcome
The English Chess Federation follows the example of FIDE for its definition of rapidplay - G10 < time control < G60 but follows the example of the USCF and doesn't have the gap between rapid and standard for moderately rated players and above. G60 and above is rated as standard regardless of rating/grading.
Having the definition of quick/rapid chess include time controls between G30 and G60 seems to me to be just "filling the gap" because I have never come across a rapidplay with a time control greater than G30. Note that the time control in the World Rapid & Blitz Championships 2019 was G15+10 (equivalent to G25):
RAPID: Swiss system, 15 rounds in the open event and 12 rounds in the
women's event. Time control: 15 minutes + 10 seconds increment per
move, starting from move 1.
The fastest rapid time control I have ever seen was G10+5 (equivalent to G15). Here in Europe the usual rapid time controls are G10+5, G15+5, G15+10, G20+10 and the occasional G30.