PD lives and votes in Houston's Council District K, one of the two districts birthed by the 2010 census, when Houston's population count breached two million and a provision in the city's charter kicked in. As we have discussed previously, K's thus far only council member Larry Green died suddenly last month, forcing a special election to fill his seat through 2019. Nine candidates queued up to take his place, including Martha Castex-Tatum (note: paywall), who had worked as his constituent liaison.
When a Council seat is vacated by death, retirement, term limits, or a member seeking higher office, here in Houston we just expect a whole crowd of hats in the ring. (I haven't really looked, but I'm sure it happens in other cities as well.) The more candidates, the less likely any candidate will receive a majority, and thus the more likely a runoff election will be required. This is especially true when there are two or more well-known candidates in the race.
Check it out, though: Castex-Tatum won handily. There will be no runoff this time. This is the exception to the rule.