England’s 1979 win over Canada set the Cricket World Cup record with 277 balls remaining. Canada were dismissed for 45, leaving England a target of 46, which England reached for the loss of two wickets in just 13.5 overs.
The arithmetic explains the record: a 60-over innings contains 360 legal deliveries, while England used 83 balls. Subtracting 83 from 360 leaves 277 balls unused. The match took place at Old Trafford during the second World Cup, when matches still lasted 60 overs per side.
The result was an eight-wicket victory, not a ten-wicket win, so the record is specifically measured by deliveries remaining rather than wickets. The unusually low target also explains why this number is so much larger than most modern records. The 2003 World Cup later produced the next-largest listed margin, with Sri Lanka defeating Canada with 272 balls to spare.