Octavio Dotel is a trade-deadline punch line at this point -- he's usually what teams get when they acquire one reliever at regular price. He's pitched for 12 different teams, which ties an MLB record, and he's pitched for five different teams over the past 18 months. He's also 37, so his career is probably winding down.
Unless he's getting better, that is.
Those are his stats with the Cardinals, and they represent a super-low walk rate and a strikeout rate that's higher than his career average. It's one of the best stretches of pitching in his career.
The real answer? Probably small-sample chicanery. But all reliever evaluation is small-sample chicanery to some extent, and a better answer might be that Dave Duncan is an honest-to-goodness pitcher whisperer. After all those teams, Dotel finally won Duncan roulette.