Is it smarter to bet on a result with a lower probability but a higher reward? Imagine you were betting:
There is a result where your calculated probabilities for a win of team 1 is 40% and the quotas are 2.0. 
Your calculated probabilities for a win of team 2 is only 35% but the quatas are 3.0... for which team should u bet?
So basically, up to which point should you bet for the result with the higher probability and is there a way to calculate that point?
 A: Expected value is used to measure how good a bet is and the statistical outcome.
$$E_1 = 40/100 \times 2 = \frac{4}{5}$$
$$E_2 = 35/100 \times 3 = 1.05$$ 
Go with team $2$.
A: You calculate the expected value of each possibility by multiplying the payoff by the probability https://en.wikipedia.org/wiki/Expected_value 
In your example:
Team 1 is 2.0 * 0.4 = 0.8
Team 2 is 3.0 * 0.35 = 1.05
Thus, Team 2 is the better choice. 
A: Soft answer: you usually want to go with whichever has the higher expectation, which as Roskiller has pointed out is team two. But this isn't always the  smartest choice. For example, would you rather pay \$1000 for a one-in-one million chance of winning 100 billion dollars (an expected gain of \$99,000), or pay 10$ for a 10% chance of winning \$1000 (an expected gain of \$90)? The second one is clearly a better deal, because you are almost guaranteed to lose the first bet, even though the expected gain is much higher.
I don't know a lot about the game theory here or anything, but often you should value certainty above raw expectation in real-life scenarios where you can't repeat the bet ad infinitum for the law of large numbers to kick in. However, in a case where the probabilities of winning are similar and neither is tiny, expectation definitely makes sense as the criterion to look at.
