Dear N:

You wrote:
> Are these sentences correct:
> 1-Yesterday there was a chance of our team losing.
> 2-Yesterday we could lose.
> 3-Yesterday we might lose.
>
> They are all supposed to mean the same thing. I want to avoid “could have” and “might have”, because by using them one implies that we did not lose yesterday. I don’t want the sentence to show whether we lost or not.
> Why did you play defensively yesterday (and why aren’t you doing it today)?
>
> “We played defensively yesterday, because we could lose.”
>
> I think it would be correct to say: “We played defensively yesterday, because we could have lost.” but then that would imply we did not lose. To make things simpler, one could imagine that we did lose.
>
It sounds like you are trying to split a hair that is too fine to split.

#1 makes sense and is standard English. #2 could make sense in an unusual context–if you were talking about your team’s attitude or something abstract–something that was unchanging. That is stretching it, though. I
would avoid it. #3 makes no sense at all. The problem is the use of the present tense.

In the case of both #2 and #3, you probably want to say “we could have lost” or “we might have lost.” In both cases, the implication is that you did not lose. In virtually every case where you use the word “yesterday” you want
some kind of past tense. If you somehow wanted to say it so that it was not clear whether you won or lost, you could say something like “We did not want to lose.” But note that it is still a past tense.

I hope this helps.