Data collected from PredictWise on September 8, 2016
The current make up of the Senate is 54 Republicans and 46 Democrats, counting
the 2 independents as Democrats.
Only 12 states are in play in having market probabilities on the PredictWise
website less than 90 percent
and greater than 10 percent. The 12 states ranked by the market probabilities
from PredictWise for the Democratic candidate are:
state  prob  now  
WI  89  R  
IL  87  R  
IN  81  R  
NH  67  R  
PA  64  R  
NV  53  D  pivot for 52 Democratic seats 
NC  44  R  
MO  26  R  
FL  23  R  
AZ  20  R  
OH  15  R  
IA  11  R  
64 = PredictWise marketbased probability of the Democrats controlling the
Senate.
If the Democrats win Nevada and all the states above it, they will have 52 seats, counting the 2 independents as Democrats. If they win Pennslyvania and all the states above it but lose Nevada, they will have 50 seats. They will still control the Senate if they win the White House. According to the ranking assumption, the PredictWise market probablility that they control the Senate is thus 64 percent (the probablity they win Pennslyvania) if they win the White House and 53 percent (the probablility they win Nevada) if they don't. If we use the PredictWise marketbased probabilty of 75 percent that Clinton wins the presidential electon, then the ranking assumption probability that the Democrats control the Senate is 0.75x64 + 0.25x53, which is 61 percent. This is close to the PredictWise marketbased probability of the Democrats controlling the Senate of 64 percent. Data collected from PredictWise on September 20, 2016
The current make up of the Senate is 54 Republicans and 46 Democrats, counting
the 2 independents as Democrats.
Only 10 states are in play in having market probabilities on the PredictWise
website less than 90 percent
and greater than 10 percent. The 10 states ranked by the market probabilities
from PredictWise for the Democratic candidate are:

state  prob  now  
WI  89  R  
IL  85  R  
IN  74  R  
PA  62  R  
NH  55  R  
NV  49  D  pivot for 52 Democratic seats 
NC  36  R  
MO  30  R  
FL  14  R  
OH  11  R  
54 = PredictWise marketbased probability of the Democrats controlling the
Senate.
If the Democrats win Nevada and all the states above it, they will have 52 seats, counting the 2 independents as Democrats. If they win New Hampshire and all the states above it but lose Nevada, they will have 50 seats. They will still control the Senate if they win the White House. According to the ranking assumption, the PredictWise market probablility that they control the Senate is thus 55 percent (the probablity they win New Hampshire) if they win the White House and 49 percent (the probablility they win Nevada) if they don't. If we use the PredictWise marketbased probabilty of 72 percent that Clinton wins the presidential electon, then the ranking assumption probability that the Democrats control the Senate is 0.72x55 + 0.28x49, which is 53 percent. This is close to the PredictWise marketbased probability of the Democrats controlling the Senate of 54 percent. Data collected from PredictWise on October 4, 2016
The current make up of the Senate is 54 Republicans and 46 Democrats, counting
the 2 independents as Democrats.
Only 13 states are in play in having market probabilities on the PredictWise
website less than 96 percent
and greater than 9 percent. The 13 states ranked by the market probabilities
from PredictWise for the Democratic candidate are:

state  prob  now  
CO  95  D  
WI  95  R  
IL  89  R  
IN  82  R  
PA  74  R  
NH  69  R  pivot for 51 Democratic seats 
NC  52  R  
NV  51  D  
MO  31  R  
FL  14  R  
OH  11  R  
LA  11  R  
AZ  10  R  
62 = PredictWise marketbased probability of the Democrats controlling the
Senate.
If the Democrats win New Hampshire and all the states above it, they will have 51 seats, counting the 2 independents as Democrats. If they lose New Hampshire but win Pennslyvania and all the states above it, they will have 50 seats. In this case they will still control the Senate if they win the White House. According to the ranking assumption, the PredictWise market probablility that they control the Senate is thus 74 percent (the probablity they win Pennslyvania) if they win the White House and 69 percent (the probablility they win New Hampshire) if they don't. If we use the PredictWise marketbased probabilty of 80 percent that Clinton wins the presidential electon, then the ranking assumption probability that the Democrats control the Senate is 0.80x74 + 0.20x69, which is 73 percent. This is higher than the PredictWise marketbased probability of the Democrats controlling the Senate of 62 percent. Data collected from PredictWise on October 25, 2016
The current make up of the Senate is 54 Republicans and 46 Democrats, counting
the 2 independents as Democrats.
Only 11 states are in play in having market probabilities on the PredictWise
website less than 95 percent
and greater than 10 percent. The 11 states ranked by the market probabilities
from PredictWise for the Democratic candidate are:

state  prob  now  
IL  92  R  
WI  88  R  
NV  74  D  
IN  71  R  
PA  67  R  
NH  63  R  pivot for 51 Democratic seats 
MO  59  R  
NC  47  R  
FL  24  R  
LA  13  R  
AZ  11  R  
79 = PredictWise marketbased probability of the Democrats controlling the
Senate.
If the Democrats win New Hampshire and all the states above it, they will have 51 seats, counting the 2 independents as Democrats. If they lose New Hampshire but win Pennslyvania and all the states above it, they will have 50 seats. In this case they will still control the Senate if they win the White House. According to the ranking assumption, the PredictWise market probablility that they control the Senate is thus 67 percent (the probablity they win Pennslyvania) if they win the White House and 63 percent (the probablility they win New Hampshire) if they don't. If we use the PredictWise marketbased probabilty of 90 percent that Clinton wins the presidential electon, then the ranking assumption probability that the Democrats control the Senate is 0.90x67 + 0.10x63, which is 66.6 percent. This is considerably lower than the PredictWise marketbased probability of the Democrats controlling the Senate of 79 percent. 