Her most established working relationship is with the yard run by Michael and David Easterby, where she has ridden 226 times and converted 18 of those into wins. That's roughly 1 win in every 13 rides, which is modest on the surface — but the Easterby operation runs a large, competitive string, and being the trusted jockey for over 200 rides tells you something more important than the raw numbers: they keep putting her up.
Where Mason genuinely stands out is in the wet. On soft or muddy ground, she has won 8 races from just 43 rides — that's nearly 1 in every 5, almost double her overall rate. Whether that's instinct, technique, or a feel for how horses move when conditions get demanding, the numbers suggest she has something that works when the ground turns against most jockeys.
She has also shown she can perform on the big stage. Newmarket is one of the most prestigious and technically demanding tracks in the country — a long, straight, unforgiving course where there is nowhere to hide. Mason has won 3 races from 7 rides there, which is an exceptional return by any measure. Winning nearly half your races at a track like Newmarket is the kind of record that gets noticed by trainers with serious horses.
Her partnership with Filey Beach — one win from three races together — is still developing, but it's worth watching. The early signs of a jockey-horse combination that clicks can often be spotted before most people are paying attention. At 247 career winners in four years, with her numbers moving in the right direction, Joanna Mason is a name worth knowing now.
| Course | Races | Wins | Win rate |
|---|---|---|---|
| Southwell | 106 | 9 | 8.5% |
| Newcastle | 95 | 5 | 5.3% |
| Beverley | 51 | 10 | 19.6% |
| Wolverhampton | 46 | 5 | 10.9% |
| Pontefract | 38 | 6 | 15.8% |
| Redcar | 31 | 4 | 12.9% |
| Doncaster | 28 | 3 | 10.7% |
| Ayr | 28 | 2 | 7.1% |
| Thirsk | 27 | 2 | 7.4% |
| York | 25 | 1 | 4% |
| Ripon | 21 | 3 | 14.3% |
| Catterick Bridge | 21 | 1 | 4.8% |
| Musselburgh | 20 | 4 | 20% |
| Carlisle | 18 | 2 | 11.1% |
| Chester | 15 | 1 | 6.7% |
| Hamilton Park | 15 | 0 | 0% |
| Nottingham | 13 | 1 | 7.7% |
| Ascot | 8 | 0 | 0% |
| Newmarket | 7 | 3 | 42.9% |
| Chepstow | 5 | 1 | 20% |
| Wetherby | 5 | 1 | 20% |
| chelmsford | 5 | 0 | 0% |
| Epsom Downs | 3 | 1 | 33.3% |
| Newbury | 3 | 0 | 0% |
| Windsor | 2 | 1 | 50% |
| Goodwood | 1 | 0 | 0% |
| Haydock Park | 1 | 0 | 0% |
| Leicester | 1 | 0 | 0% |
| Lingfield Park | 1 | 0 | 0% |