12

On July 12th 1966 in Group 2 of the World Cup, West Germany beat Switzerland 5-0 at Hillsborough in front of 36,000. Two of the Swiss team were dropped from the side having broken a "curfew", staying out in the night life of the Steel City!
Brazil beat Bulgaria 2-0 despite Pele being kick from pillar to post by the opposition defender Zhechev. Pele got his own back by scoring the first goal of the tournament from a swerving free kick and he thus became the first man to score a goal in three consecutive WC Finals. Pele did not play in the next match following his injuries-Brazil retired early.

July 12th 1974 was when Bill Shankly retired from his managership at Liverpool, announcing that he was finding the job too much pressure. Ray Kennedy was signed by Liverpool from Arsenal for £180,000 and might have helped Shanks relax a bit?

2018: Trippier wore the 12 shirt yesterday for England and scored a wonderful goal.
It was the 12th goal goal scored for England in this World Cup.
It was Trippier's 12th cap,
and the first goal scored by a number 12 at this World Cup and
the first goal ever scored by a number 12 for England in any World Cup and 12 goals were scored by Tottenham players at the World Cup.