In the general financial market, I don't know if the chartist used any holdout sample to test their forecasting techniques. A few people I know who use charts all just learn some patterns from books or other people, then eyeball the chart, and predict the whatever from that. In my opinion, this is just guessing and just as good/bad from the general public or sentiment. And just happened all these chartist I know are stock brokers, who really are not known to predict the market well.
And it just happened that I know a few fundamentists very well and they generally can consistently outperform the market. I think that if you invest knowing the true reason for the decision, you can sleep better without needing to look at the market everyday to check if your "pattern" hold.
For betting races, the closest to "technical" betting is arbitrage between pools.