Not have a dog’s chance
Definition 1 of 1
Pro Tip 1/3Extreme Improbability
Used to express that something is extremely unlikely to happen or is virtually impossible. 
Even with hard work, you don't have a dog's chance of becoming a pro athlete at 40.
Pro Tip 2/3Not Literal
The phrase doesn't involve dogs; it’s a metaphor for a very low probability of success. 
I'm so behind in the race, I haven't got a dog's chance of catching up.
Pro Tip 3/3Negative Tone
Conveys a pessimistic outlook and is usually used to manage expectations. 
With the market crash, our investment doesn't have a dog's chance of paying off.