It is preferable to have a small but certain advantage than a mere potential of a greater one
(Atasözü) Something we have, or can easily get, is more valuable than something we want that we may not be able to get; we shouldn't risk losing something sure by trying to get something that is not sure
Johnny has a job as a paperboy, but he wants a job in a gas station. His father says that a bird in the hand is worth two in the bush.
it's best to go with what you have for certain then to wait for something better that you might never get