I'm going to cross post my #analysis from the US-SEN 2020 thread.
Kentucky: Fool's gold for Democrats, but Republicans won MI, PA, and WI last year, so what the Hell. McConnell has only really won a decisive victory twice, the first in 2002, the second in 2014, the worst year for Democrats in damn near a century. Given the fact Grimes will be term limited out of the Secretary of State spot in 2019, I think it's very likely she runs for Governor and Andy Beshear runs for re-election. A second term AG Beshear can easily run from cover. I also wouldn't rule out McConnell retiring, especially if 2018 isn't a good year for the GOP