"The match would have started by now." Could you give me a situation we could use this sentence?
If it hadn't started raining an hour ago, the match would have started by now.
If the coach had arrived on time, the match would have started by now.
If you're asking about the future perfect tense, everything I can find out about it uses 'will have' instead of 'would have', as in
"We're running late and we won't see the beginning, because the match will have started by now."
However, there is an example given in the comments that might answer the question:
"The Mayor was supposed to start her speech at noon but she's been delayed so now she'll speak at 1 pm -- so the match, which would have started at half-past noon, will now start at half-past one."