For example, let’s say one team starts off slow and falls behind early, but then they suddenly make a strong comeback. The game becomes close, and at that point the betting line gives you pretty good value if you pick them to win.
Would you place your bet on that team just because they have the momentum on their side, or do you think it’s just an illusion and not really a factor in the outcome?
It depends on the team they are playing against or with, this alone will determine or tell if I will be placing my bet on them of the other team.
Momentum doesn't equal winning, and in sports betting, being the reigning team at that moment in time does not mean that the team will be able to beat another better team they are or will be playing against, it's just like Southampton gaining the momentum for beating both Chelsea and Manchester united in a row, and are going to face Manchester city and Arsenal in their next two games or matches, do you think they can withstand this two clubs, if I was going to bet on any of this two matches or both, i will be betting on Manchester city and Arsenal respectively, even though I'm aware that there is a chance that Arsenal may mess up, I still believe that betting on Southampton on such a match is more risky than betting on Manchester city and Arsenal respectively.
So in the nutshell, and to be sincere, I bet on who has better chances of winning a match, and not who is reigning at that particular moment.