All three major election models give Republicans a six-in-ten (or better) chance of picking up the six seats the party needs to reclaim the Senate majority, with just 29 days left before voters head to the polls on Nov. 4.

The Washington Post's Election Lab is the most bullish on Republicans' chances, pegging it as a 78 percent probability they win control of the chamber. LEO, the New York Times' Upshot model, has the chances at 60 percent -- roughly the same as Nate Silver's FiveThirtyEight at 59.4 percent.  The overall predictions of Election Lab and FiveThirtyEight are virtually unchanged from a week ago (click here to see how things looked then) while the LEO model is less optimistic about a Republican-controlled Senate this week than it was last week (67 percent probability on Sept. 29.)

Of the 11 marginally competitive contests -- we do not include Republican open seat takeover opportunities (more like virtual certainties) in Montana, South Dakota and West Virginia in that category -- all three models agree on nine of the races including four seats that would be additional GOP pickups, bringing their total to seven pickups. Those seats are:

* Alaska: All three forecasts show former state Attorney General Dan Sullivan (R) with between a 68 percent and 77 percent chance of beating Sen. Mark Begich (D).

* Arkansas: The models suggest that Rep. Tom Cotton (R) is increasingly likely to beat Sen. Mark Pryor (D). Both LEO and Election Lab put Cotton's chances over 80 percent.

* Iowa: The models all show state Sen. Joni Ernst (R) as a slight favorite to claim Sen. Tom Harkin's (D) open seat. Both FiveThirtyEight (59 percent Ernst win) and LEO (55 percent) are somewhat guarded in their optimism for the Republican's chance; Election Lab is far more bullish, pegging Ernst with a 76 percent probability of victory.

* Louisiana: Sen. Mary Landrieu's (D) odds of winning reelection continue to get worse. No model has the probability of a Republican takeover lower than 74 percent.

The three models disagree in two states: Kansas and Colorado.

In Kansas, where an NBC/Marist poll released Sunday showed independent candidate Greg Orman with a 10-point edge over Sen. Pat Roberts (R), LEO (64 percent independent) and FiveThirtyEight (65 percent independent) lean toward an Orman victory. Election Lab still gives Roberts a 76 percent chance of winning.  (Worth noting: Orman has not said which party he would caucus with if he does win. But he is quite clearly Democrats' best chance of a pickup; none of the models paint an optimistic picture for Democratic hopes in Kentucky or Georgia.)

In Colorado, Election Lab (70 percent Republican) and, more narrowly, FiveThirtyEight (53 percent) see Rep. Cory Gardner (R) as the favorite. LEO basically rates the race a pure toss-up, but gives the slightest of edges -- 51 percent chance of victory -- to Sen. Mark Udall (D).

If you assume Orman wins (and caucuses with Democrats) and Gardner wins, that would be a net seven seat pickup for Republicans -- giving the GOP 52 seats and Senate control come January.

Twenty-nine more days to go.