Here's what the Cola ThinkTank says happens if the following pairs make it through the mayoral primary to the general:

1) Mike McGinn vs. Peter Steinbrueck: McGinn.

This is the best-case scenario for McGinn because it lets McGinn highlight his urbanist message, allowing him to paint Steinbrueck as a frumpy return to the past.

2) Ed Murray vs. McGinn: Murray.

Murray splinters McGinn's progressive base.

3) McGinn vs. Bruce Harrell: Harrell.

Harrell represents change; Harrell is also the best brawler of the challengers which undermines McGinn's fisticuffs advantage over the rest of the amiable pack. 

Bruce Harrell

4) Harrell vs. Murray: Murray.

Murray gets the progressive vote, plus he steals Harrell's business base.

5) Steinbrueck vs. Harrell: Harrell.

Harrell flanks Steinbrueck from the left (social justice) and the right (corporate background)—which plays to Harrell's natural stengths, leaving Steinbrueck with a small contingent of neighborhood activists.

6) Steinbrueck vs. Murray: Murray.

It's another version of McGinn beating Steinbreuck or Harrell beating Steinbrueck: Murray isolates Steinbrueck as a Charlie Chong figure while highlighting his own progressive and mainstream bona fides. 

We've got Murray winning every contest, so a couple of reality checks on that : 1) He can be a hothead and with aggressive candidates like McGinn and Harrell coming at him, Murray could easily stumble; 2) That weakness is compounded by the fact that he's not as well versed in city issues as McGinn, Harrell, or Steinbrueck. (Murray's other gargantuan problem: The session in Olympia isn't likely to end for another two months, which keeps him out of the fundraising game.)

As for Harrell, who we also have winning a lot, there are some reality checks there too. First and foremost, his polling numbers are sluggish, so the odds are long on getting through to the general. Second, and this connects to the first point, people don't really know who he is—which means his opponents will have an easier time defining him, as opposed to, say, going against Murray, who's known as a gay rights champion. Of course, this also could play to Harrell's advantage if he can define himself ... which he's currently trying to do: Meet Bruce Harrell, the social justice candidate.