bet on the wrong horse

1. Literally, to bet money on a horse that does not end up winning a race. Man, there goes my money. I always seem to bet on the wrong horse at these things. I heard she bet on the wrong horse at the Kentucky Derby and lost a boatload of cash. If you put down that much money and bet on the wrong horse, yeah, your wife is going to be furious with you!

2. To support or select someone or something that ultimately proves to be unsuccessful, problematic, troublesome, or incorrect. I truly believed our candidate would win this election, but it looks like I bet on the wrong horse. I know you're confident about the success of this product, I'm just worried you might be betting on the wrong horse. You really bet on the wrong horse when you picked that swimmer to win the race—he didn't even get a medal!

3. To anticipate some future event incorrectly. When I was a kid, I thought by the time I grew up we'd have walking, talking robots doing everything for us. Looks like I bet on the wrong horse. I moved to this neighborhood because I thought it would experience a renaissance, but, as you can see, I clearly bet on the wrong horse. A: "I had high hopes for Lisa when we offered her the management position." B: "Well, you bet on the wrong horse then because she is woefully disorganized as a manager."