MIAMI — Alaska  announced new services out of Seattle on Tuesday, fresh on the heels of a similar announcement made by Delta on Monday.

Alaska announced on Tuesday that it would begin service to Detroit, New Orleans, and Tampa. The flights will be served with Alaska’s fleet of 737s, and inaugurals for each are set for September 4, June 12, and June 20, respectively. For the latter two cities it’ll be the first non-stop service to the Emerald City. Detroit, however, is already served by rival Delta Air Lines – the latest cross-pollination by Alaska into an existing Delta hub (or vice-versa, for that matter).

Speaking of Delta, the carrier yesterday announced new or expanded service to multiple cities out of Seattle. Anchorage will receive a boost of one daily flight per week, and a third seasonal daily roundtrip in the summer.

Palm Springs will receive daily seasonal winter service, while Jackson Hole, Wyoming and Tucson, Arizona will receive once weekly seasonal service. It has also announced plans to add an additional nonstop flight to Honolulu and an additional seasonal daily nonstop to Anchorage, bringing the carrier to twice daily service to Honolulu and thrice daily on the Alaska Airlines trunk route to Anchorage (twice daily year round).

The two carriers have been locked in an increasing battle over Seattle. Delta has been adding extra service aimed at bulking up feeder traffic for its ambitious international expansion in the city. The carrier announced a slew of new flights to Asia last year, all of which will begin by the end of the summer 2014. Alaska, meanwhile, responded by creating a new focus city in Delta hub Salt Lake City in December, along with adding new routes and additional capacity to existing ones.

Delta will be competing with Alaska on a number of the routes, but it also pits the carrier against Southwest and the new American – particularly in Phoenix. As the graphic below shows, the Seattle-Phoenix route is currently a three-way fight for origin and destination (O&D) traffic between Alaska, US Airways, and Southwest, with Delta being the largest player on the route without a nonstop.

However, it’s important to note that both Southwest and US Airways (by virtue of a merger with American) will see costs pretty much continually rising over the next year and a half. These rising costs will allow Delta to be competitive on the route, especially if can steal away frequent flyers from Alaska in Seattle.


But the broader play here is still Delta attacking Alaska in Seattle and connecting the dots with a lot of the big Western markets. One of the important figures that can be used to analyze the competitive dynamics of Delta’s Seattle build up is its relevance factor.

Essentially, this percentage figure measures how many of Alaska Airlines’ O&D customers Delta is “relevant” (offers competitive service) to. And every time Delta adds a big West Coast market, it only increases that number. Consider that Delta is about 40% of the size of Alaska by capacity (available seat miles) and 30% by daily flights and seats (79 peak day departures versus more than 250), but it is already relevant to close to 50% of Alaska’s Seattle customers.

So as Delta builds up towards the inevitable endpoint of a hub in Seattle, expect to see more and more markets like Phoenix added to the mix.