If Lee gets 30 percent of the first-place votes, most observers (including his opponents) agree that he's going to cruise to victory. But if his first-place total is closer to 20 percent, and one or more of the other candidates are within five points, it's going to be a lot closer.
Here's the bottom line: If you don't want to see a repeat of the late 1990s, when Willie Brown was mayor and City Hall was for sale to the highest bidder, vote for anyone but Lee — and use your three votes strategically. If you like John Avalos, put him first — but give your second-place vote to Herrera, who seems positioned right now to be the other strongest challenger. If you like Herrera, give your second to Avalos. If you like Leland Yee or David Chiu, make sure that Avalos and Herrera are also on your slate.
Fill out all three votes. And get your friends and family to the polls. Because turnout is projected to be low, which helps Lee — and the race may well be decided on the basis of who shows up November 8th.