current point spread of US house election

[rob in cal]

  If we were to handicap the upcoming Nov election in terms of numbers of seats won by each party, I wonder what the spread would be.  Right now I'm thinking Dems with a net gain of something like 40 seats.  It would be interesting to have a rolling number, like a point spread, for this, to see it go up and down as we get closer to game time, sorry, election day.