Trading out of trouble
I agree that traders can often overlook the need sometimes to "change horses in mid stream".Looking back at my own records I notice that nearly 50% of my trades start with a bet on the Match Odds market where invariably I have backed the heavy underdog (perceiving value, wrong prices, etc). Equally noticeable is that my pre match selection is not particularly prescient as the fav scores first on many occasions. Ooops!
Now because I have staked the trade in such a way as to favour the dog winning with cover on a possible win to the "wrong" team it would appear that I am heading for misery, failure and a further dent in my reputation. But, as Ian points out in his post, the initial idea for a trade may be doomed but you can switch to another trade entirely; this may involve a number of approaches - hedging for red in Match Odds, entering Over goals markets for example, even laying the favourite at short odds to gain additional leverage should "your dog" team get a goal back.
Whatever you decide, DO IT! Don`t bemoan the fact that your favoured side hasn`t read your pre match script. Get the metaphorical pen out, delete some scenes and re-write new ones.