Before that what was the rule? The bench HAD to play lower grades?
History of the replacement/interchange rule
In 1963 Teams were allowed to replace a maximum of two injured players during the first half of a match and including halftime
In 1970 Two injured players were allowed to be replaced at any time during a game, provided that the replacements had played at least half of a lower-grade game that day
In 1981 Four replacements of players on the field are allowed during matches
In 1988 Two fresh replacements were now allowed, previously they had had to have played in a lower-grade game earlier.
The interchange rule was introduced in 1991, it allowed four players, consisting of up to two fresh reserves and a minimum of two players who had played half a game of the preceding Reserve Grade or President's Cup, unlimited interchanges during a match. The rule's main purpose was to reduce the risk of blood-borne diseases being spread but an angry public reaction forced a modification in April. The rule changed to allow a total of four players to be available for a maximum of six interchanges during a match.Players sent to the ‘blood-bin' would not count among these six interchanges.
In 1996 unlimited interchange was reintroduced.
Limited interchanges were reintroduced in 2001 capped at 12
In 2008 The maximum number of interchanges that could be made from a pool of four replacements was reduced from 12 to 10