Worth noting that in TN/WV in 2018, polls overestimated Democrats by 6 points, meaning this race is still a tossup and not Lean R.
Polls in late October/early November overestimated Democrats by 6. If a public poll finds Beshear ahead by 9 in October, that's a different story, but in August, Bredesen was still ahead. Plus, Kentucky polls have more consistently overestimated Democrats.
The thing is with polls in Kentucky is that the topline Dem percentage tends to be accurate. Grimes was polling at 42% in 2014 KY-Sen, she got 41%. Conway was polling at 43% in 2015 KY-Gov, he got 43%.
Also, there have been times where polls were fine in Kentucky: 2016 Kentucky Senate polls actually slightly
underestimated Gray, for example.