Chess Forum / General Topics / March 2008

The effects most certainly are not `mathematically identical'.  With
what you're calling `Bronstein', if you have five seconds on your
clock at the point when I make my move, you must move within five
seconds (which you'll get back for your next move).  With what you're
calling `delay', you have ten seconds to make your move.

Dave.

(See the second-to-last pagaraph below)

Do you have a reference showing that the name "Bronstein" is
correct for the former and that the name "Standard USCF delay"
is correct for the latter?  In particular, id there any evidence
that the latter was invented by the USCF and not Bronstein?

Here are descriptions of six ways to handle delays, followed
by what I believe are the proper names for each.  I welcome
any discusion/corrections/references concerning whether I
got the naming right.

NO DELAY, NO INCREMENT: When you start your clock, it starts
decrementing. (Analog chess clocks act this way).

DELAY: When you start your clock, it freezes for N seconds
and then starts decrementing.

INCREMENT AT START (IAS): When you start your clock, it
instantly increments by N seconds, then starts decrementing.

INCREMENT AT END (IAA): When you start your clock, it starts
decrementing.  When your opponent starts his clock (thus
stopping yours), your clock instantly increments by N
seconds.

INCREMENT AT END WITH LIMIT (IIEL): When you start your
clock, it starts decrementing.  When your opponent starts
his clock (thus stopping yours), your clock instantly
increments by N seconds or the amount of time you used,
whichever is smaller.

DUAL INCREMENT (DI): When you start your clock, the clocks
of both players instantly increment by N seconds, then your
clock starts decrementing. When your opponent starts his
clock (thus stopping yours), the clocks of both players
instantly increment by N seconds, then your opponent's clock
starts decrementing.  N is half the size of the other schemes.

-----------------------------------------------------------

I believe that the following naming is correct, but I
welcome corrections -- especially with references.

DELAY is properly called Bronstein Delay.  It is sometimes
called Andante, US-style or USCF-style,

INCREMENT AT START is properly called Fischer Increment.
It is sometimes called FIDE-style, bonus, or progressive.

INCREMENT AT END is, as far as I can tell, only a
theoretical possibility, not used in actual play.  I can't
think of any advantage it has over Fischer Increment.

INCREMENT AT END WITH LIMIT is properly called
Bronstein Increment.  It is sometimes called Adagio or
non-cumulative addback.

DUAL INCREMENT is something I just invented on the spot.  
If nobody else thought of it first and it caches on,
I claim the name "Macon Increment" <grin>.

Bronstein Delay and Bronstein Increment have a subtle
real-world difference.  Imagine two players, each with five
seconds left. One is using Bronstein Delay and the other
Bronstein Increment.  The Bronstein Delay player has ten
seconds before he loses on time -- five seconds with his
clock frozen and five seconds as it decrements down to zero.
The Bronstein Increment player has five seconds before he
loses on time.  Adding 5 seconds at the very start of the
Bronstein Increment or allowing the Bronstein Increment
player to run out of time then increment back to where he
still has time would make them mathematically equivalent,
but there would still be a big psychological difference.

Does anyone know exactly how Bronstein described his
invention?  I rather suspect that he described either
Bronstein Delay or Bronstein Increment and that an
electronic chess clock manufacturer created the other
variation.