idiomatic expressions

[Avalon]

Ksequen is absolutely right about all idioms..being a teacher of English in Brazil, I can state that the explanations given by ksequen are all precise.

[BobK]

are there someone could you help me to translate the meaning of an idiom on a sentence like this:
sufficient variety must be created if one wishes to solve problem, it is important to back a number of horses

There's an exact(ish) equivalent to that: "to play the field" - which uses slightly unusual meanings of both 'play' and 'field':

play - back, put money on
field - all the horses in a race

b