https://www.amazon.com/Dr-Beat-Racetrack-William-Ziemba/dp/0...

His idea is that the odds (on the tote board) to win can be used to make a more accurate predictor for winning place and show than the place and show odds on the board. What you notice is that maybe two times a day at the track you find a horse which is favored to win and the show bet pays almost as much as the win bet and you place a Kelly-sized bet on that one.

I've found a few opportunities of that sort at the local harness racing track.