|Hillary Clinton||11 to 15||45.7%|
|Marco Rubio||4 to 1||15.8%|
|Donald Trump||7 to 1||9.9%|
|Bernie Sanders||9 to 1||7.9%|
|Jeb Bush||13 to 1||5.7%|
|Ben Carson||20 to 1||3.8%|
|Ted Cruz||25 to 1||3.0%|
|Chris Christie||40 to 1||1.9%|
|John Kasich||50 to 1||1.6%|
|Carly Fiorina||60 to 1||1.3%|
|Mike Huckabee||75 to 1||1.0%|
|Rand Paul||150 to 1||0.5%|
|Martin O'Malley||175 to 1||0.5%|
|Bobby Jindal||200 to 1||0.4%|
|Rick Santorum||225 to 1||0.4%|
|Lindsey Graham||250 to 1||0.3%|
|George Pataki||300 to 1||0.3%|
Note: I adjusted the percentage chance of winning to add up to 100% - the bookie takes a cut. That puts the overall race at 54% for Democrats and 46% for Republicans, which is pretty close to a 50/50 coin toss.
The way this likely goes is that Ben Carson wins Iowa and Donald Trump wins New Hampshire, then the Republican Party establishment gets down to the gritty and uncertain business of putting through their most viable candidate, who at this point in the race looks to be Marco Rubio.
The worst bet on board? Bernie Sanders - if Hillary Clinton falters, the Democrats will find someone else. The best bet? Ben Carson - he may not ultimately win but I think you'll be able to cover at better odds after Iowa.