Manchester City apparently employs 10 analysts to do this stuff and Chelsea has 32 million “player actions” based on over 13,000 games in its database according to a report by Rory Smith in The Times.
The interesting statistic he emphasised in his piece was on when to make a substitution. Brett Myers, an ex-pro footballer from America, now an Assistant Professor at a business school in Pennsylvania, has come up with a theory.
He says if your team is losing at half-time you must make your substitution before the 59th minute. If you are still losing make another before the 73rd minute and if that doesn’t change things your final one in the 79th minute.
Following this 58-73-79 rule gives your team a 40-45% chance of success compared to only 18-22% if you don’t. In other words it doubles the odds from 1 in 5 to 2 in 5.