spoil his chances of doing something, especially secretly or maliciously - British
This phrase originated as 19th-century slang. Early examples of its use suggest that the pitch referred to is the spot where a street performer stationed themselves or the site of a market trader's stall.
1973 - Elizabeth Lemarchand Let or Hindrance - He’s a decent lad... he would never have
risked queering Wendy’s pitch with Eddy.
Related Idioms and Phrases :
In Queer Street
in difficulty, especially by being in debt - British informal - dated
Queer Street was an imaginary street where people in difficulties were supposed to live. The phrase has been used since the early 19th century to indicate various kinds of misfortune, but its predominant use has been to refer to financial difficulty. The use of
QUEER to mean a male homosexual is a separate development.
1952 - Angus Wilson - Hemlock and After – He enjoys a little flutter and if he finds himself in Queer Street now and again, I’m sure no one would grudge him his bit of fun.