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.

In any given general election, roughly a dozen or two of the 100 Iowa House districts are in play. A first look through the list of candidates who qualified for the primary ballot suggests that this year, fewer Iowa House districts will be competitive than in 2010 or 2012. Republicans have failed to field a candidate in 32 of the 47 Democratic-held House districts. Democrats have failed to field a candidate in 26 of the 53 Republican-held House districts.

Although a few of these districts may see major-party candidates nominated through special conventions after the primary, it’s rare for late-starting candidates to have a realistic chance to beat an incumbent. (That said, two Iowa House Democrats lost in 2010 to candidates who joined the race over the summer rather than during the primary campaign.)

After the jump I’ve enclosed a full list of the Iowa House districts left unchallenged by one of the major parties. I highlighted the most surprising recruitment failures and what looks like a pattern of uncontested House seats in Senate districts that will be targeted by both parties, which may reflect a deliberate strategy. House incumbents with no fear of losing may slack off on GOTV in one half of a Senate district where every vote may count.

A future post will focus on the ten or fifteen Iowa House races likely to be most competitive this fall.