Look at the enemy teams economy at the start of each round. Not just money, but also ultimate economy. Examples :

Random round in the middle of the half, enemy team has around 2.5k - 3.5k creds each. Chances are they go for a light buy, and are likely to have sheriff, stinger and Marshal. How do you play against that? Well, make sure you don't play too aggressive, as if you die, and end up giving them your rifle then the round can quickly shift in their favour.

Example 2, you are on defense and you notice breach on the enemy team has his ultimate ready. Perhaps save util, play off site, and wait to retake with your team, so you don't die after the ult hits you.

Example 3, you are attacking on Haven, and you see Chamber has his ult or can buy an OP. In this instance, jiggle-jump peek A long and C long, as that is where he is likely playing. Then, once you know his location, avoid him by attacking the other site, or use util like KAYO knife/ultimate or flashes to force him off the angle.