Counting the number of July 1 marchers is difficult for those who want to do it right because, as statistics expert Paul Yip Siu-fai puts it, whatever he announces, everyone says it's wrong.
The University of Hong Kong social work professor said he had thought seriously about not counting this year's marchers.
It has been a thankless task since his first one in 2003, when half a million took to the streets against the controversial national security bill, which was eventually shelved.
'Whatever I do, people politicise it,' Yip said. People were obsessed with the biggest number, he said, so the party releasing the largest figure should be viewed with scepticism.
'Everyone likes the big numbers, including your newspaper. A big number is a good number because it's sensational. I have considered not doing it ... it's hard to swallow people's accusations, especially when they aren't reasonable,' he said, referring to some rally organisers' remarks in previous years that Yip had 'deflated the number'.
But after much consideration, Yip decided he could not abandon a job he has done for nine years.
His method involves counting the number of people who pass a certain point in Causeway Bay and Admiralty for a minute at 15-minute intervals. However, this does not cover protesters who start at Victoria Park and leave the march before Yip's first checkpoint in Causeway Bay.