if the democrats win in michigan, that's a hold, not a pickup.

the best chance the democrats have of flipping a seat is north carolina.

i would not consider iowa, kansas, texas or alaska to be seriously in play.

ohio and maine both remain distant longshots for the democrats.

so even if they somehow get north carolina, ohio and maine, they still are in the minority. the republicans still control the senate.

let's say north carolina is about 55%, ohio is about 45% and maine is about 40%. those are probably overestimates. 

.55*.45*.4 = 0.099, to start.

then, they'd also have to hold michigan and georgia. let's peg that at 55% and 65% respectively.

.099*.55*.65 = 0.0353925

then, let's say alaska is 30% and iowa is 25%.

.0353925*.3 = 0.01061775

0.01061775*.25 = 0.0026544375

giving the democrats a 4% chance that they can get within striking distance to start is a fair analysis.

the chance that they're going to actually win is practically zero.