Official Government statistics, based on returns from schools, put the total at 4,980 vacancies in January. But newsdesks demanded up-to-date figures at the start of the new school year.
ITN was first out of the traps, reporting 5,600 unfilled posts in late July, based on returns from 100 councils - equivalent to 8,400 vacancies across England.
Two weeks later, the Independent predicted the figure had dropped to only 4,600 positions across England and Wales, calculated from returns from 168 authorities.
Undeterred, the Guardian estimated last week that there were 3,500 full-time vacant posts in 100 authorities it surveyed. There was no extrapolated figure nationally.
By Monday, the Press Association claimed the figure was 2,862 vacancies, based on a survey of 127 authorities. Again, there was no attempt to offer a national figure.
What, then, is the true total? The TES survey carried out with Secondary Heads Association, published last week, indicated there were 5,000 vacancies.
It was the only survey to ask heads' views on the quality of staff, and revealed concerns about one in five appointments. All these figures, however, pale in comparison to one statistic: the number of surveys carried out this summer compared to last rose by 500 per cent.