After all, 139 of Williamson's wins have come from horses trained by his father, Phil - almost all of them trotters.
But Williamson junior is still waiting to round all four bases for his 500th ''home run''.
The 25-year-old has been stuck on 499 wins since Duchesse de L'Amour won at Timaru three weeks ago, although he brushed off suggestions he was stringing out the moment like a farewell tour from a retiring celebrity.
''It's dragging out but it's adding to the hype - more people are getting interested,'' Williamson joked.
''It will come when it comes - I'm not too fussed about it. Eventually it will come.''
His father prepares Springbank Eden in race 7, which provides Williamson with the best chance of nailing win No 500 tonight.
The rising 4yr-old has a trio of seconds to his name from his last three starts.
''He's just going good enough to get rolled, but this is probably the weakest he's been against of late,'' Williamson said.
''He should be a good chance, but it will just come down to trip and whatnot - if he has to do too much work, he's vulnerable, but he still should be really hard to beat.''
The son of Angus Hall has been starting from the unruly mark since late March and the extra space seems to suit him at the start.
''He stepped really good the other day and I couldn't see that being too much of a concern.
''If he's slow away, he's going to find it hard, but if everything goes right for him, he should probably win.''
Williamson expects he will send the gelding on a searching run during the race, as his best spot is handy to the lead.
''He's quite tough and sticks to his guns quite good. With his gait, he can't really handle a really sharp sprint or he goes a wee bit rough.
''Stamina's his go at the moment - provided he could get away, we'll be up around them at some point.''
There is a chance his 500th win could come earlier in the night, as he teams up with Zenmach in the opening event, a 2yr-old 1950m mobile pace.
The Mach Three gelding was bought by the Central Courage Syndicate this week as a replacement for the United States-bound Al Raza.
It will be Williamson's first drive behind Zenmach, who is now trained by Geoff and Jude Knight.
''I've seen a couple of trials and it looks like it's got enough ability. Just with it being a 2yr-old race, I don't know how the others go.
''The syndicate has a lot of luck so hopefully it continues with this one.''
Williamson said Elusive Flight (race 3) could ''spice up'' First4 bets, if the 6yr-old is in the right mood.
