The problem with betting during a match is that the odds change rapidly, requiring patience before you actually place your bet. I personally prefer betting before the match, as I've often placed bets while they're in progress, and honestly, it takes time to get the numbers I want.
Moreover, I prefer multi-betting, so I'll choose matches that I think have a high chance of winning. However, this doesn't always work, as I've also lost quite a few times. Predicting a match with certainty isn't easy, as luck can sometimes play a role.
You can click the accept odds changes if you want to easily lock in your bet on live match. The odds only changed very minimal with a minutes or seconds interval on the game.
Unless you are betting on fighting match like MMA or Boxing while on your betting time a player hit a massive blow that might end the game quickly then the odds might change significantly.
However on regular sports, odds changes is very minimal on live.