This article is from the Formula One Motor Racing FAQ, by mitchmcc@ultranet.com (Mitchell McCann) with numerous contributions by others.
Introduced for the 1996 season, the 107% rule is designed to
weed out the slower cars in the field. Any driver whose best
qualifying time is more than 107% of the pole-sitters time will
not qualify for the race. For example, if the pole time is 1 min
40 secs (100 seconds), then any car slower than 1 min 47 seconds
(107 seconds) will not be in the race. The rule does allow for
some discretion on the part of the stewards and this discretion
has so far been exercised just once for Pedro Diniz at Melbourne
'97.
 
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