That is the way probability math works. It isn't creative. It is easier to see with flipping coins. In a fair coin toss you have a 50% chance of heads and 50% chance of tails.
If tossed twice, you have a 25% chance of both tosses being heads, a 25% chance of both tosses being tails and a 50% chance of a split.
If tossed three times, you have a 1/8th chance of all three tosses being heads, a 1/8th chance of all three tosses being tails, a 3/8ths chance of a 2 heads/1 tail split and a 3/8ths chance of a 2 tails/ 1 head split.
If tossed 4 times, you have a 1/16th chance of all heads, a 1'16th chance of all tails and a 14/16th chance of some kind of 2/2 or 3/1 split. So you get to that 1/16th chance by multiplying 1/2 times 1/2 times 1/2 times 1/2 = 1/16th.
The football odds work the same way. If all three games are judged an 80% chance of losing that particular game then to find the chances of losing all four (like getting all four heads in a coin flip) is to multiply .8 times .8 times .8 times .8 which equals a .41 chance of losing all 4. So the chance of winning at least one game is the converse, i.e. 59%. Now the chances of SC winning all four if you keep the same 80% odds of losing any particular game, is miniscule, like not even 1%. But winning one is doable if the chances of winning each particular game is 20%.
Now obviously you can quibble with the 80/20 odds. Maybe the odds of SC beating Florida is worse than 20%. If so, give me the odds for each of the four games and I will give you the math for at least one upset.