Thanks to Iowa’s non-partisan redistricting process, we have an unusually large number of competitive state legislative districts. In any given general election, depending on candidate recruitment, between one dozen and two dozen of the 100 Iowa House districts could be up for grabs. Democrats and Republicans spend big money on a much smaller number of districts; this year, only seven Iowa House races involved a large amount of television advertising. But the parties and candidates invest in direct mail and/or radio commercials in many more places than that.

Republicans go into election day favored to hold their Iowa House majority, which now stands at 53 seats to 47. Carolyn Fiddler has pegged seven “districts to watch” at her Statehouse Action blog, and in September, the Des Moines Register’s Jason Noble discussed five districts he viewed as “key to Iowa House chamber control.” I see the playing field as much larger.

Follow me after the jump to review 20 Iowa House seats that will determine control of the chamber for the next two years.

Caveat: most years, there’s at least one shocking result in an Iowa House district neither party had their eye on. I’m thinking about Tami Weincek defeating a longtime Democratic incumbent in Waterloo in 2006, Kent Sorenson defeating a Democratic incumbent in Warren County in 2008, three Democratic state representatives who had run unopposed in 2008 losing in 2010, and Democrat Daniel Lundby taking out the seemingly safe Republican Nick Wagner in the Linn County suburbs in 2012. Wagner had run unopposed in the previous election.

So, while I don’t expect any of the “favored” seats discussed below to change hands, I would not rule out a surprise or two. That would be excellent news for the stealth challenger’s party.

The Daily Kos Elections team has been compiling 2012 presidential election results by state legislative district as well as by Congressional district, state by state. Last week the Iowa numbers were added to the database. I took a first stab at previewing the battle for control of the Iowa Senate next year, using data including the raw vote totals and percentages for President Barack Obama and Mitt Romney in each district.

The Daily Kos database includes Obama and Romney vote totals and percentages for each Iowa House district here. After the jump I’ve incorporated that information and other factors to predict which Iowa House districts will be competitive in 2014. Writing this post has been challenging, because every election cycle brings surprises, and many more seats in the lower chamber will be in play. Unlike the Iowa Senate, where only half of the 50 members are on the ballot in each general election, all 100 Iowa House members are on ballot in every even-numbered year. Republicans currently hold a 53-47 majority in the lower chamber.