Pls show me proof.i am confident that it started from 1996 world cup.sri lankan team used it well with opening pair jayasurya and kaluvitharana.3.15 overs field restrictions started from 96 world cup only.so comparing with old cricket days is not good.
15 overs field restriction there from long back. (even ODI started) , i saw 1992 wc with 15 overs field restrictions.
Now last 10 yrs, lot of rules changed like PP1 PP2 PP3 etc and batting pp and bowling pp etc..etc..