Tradeskill success not matching wiki formula

[Wisteso]

According to the wiki, doing a combine of something after being the exact 'trivial' skill amount should succeed 66% of the time, but this was definitely not even close to the success rate I had when doing quite a lot of Heady Kiola combines. Other combines seemed to mirror this as well but I don't have as much data on those.

Over the course of probably 100 combines I observed about a 90-95% success rate at 46 skill, not 66%. I suppose I could have 1 in a million luck, but seems more likely that the wiki is just not correct. I never recall having only 66% chance when trivial in retail either.

Anyone know what's going on here?