Board Thread:Game Discussion/@comment-2405:204:B201:DC69:985C:1F30:9002:B598-20181013161634/@comment-37157068-20181013175614

The explanation is easy. Sponsored TT are easily visible from the home screen and often they are additionally advertised. So probably more casual and novice players take part in them, setting thousands of poor results which drive you up as the time passes. In contrary, to take part in a WTTT you first have to find it :)