Only roll when you need to be stronger
Basically, the purpose of rolling champions is to help players upgrade the strength of their team. The easiest way to gauge the strength of your team is to look at the results after each round. If players are on a long winning streak (more than 4 rounds), then your team is extremely strong. In the case of continuous losses (4 or more consecutive losses), it means your team is very weak.

When on a losing streak, the best way to avoid losing health is to roll and find ways to upgrade your team. If you are on a winning streak, leveling up will be much more effective than rolling for champions. By leveling up, players will have the opportunity to buy valuable champions with great strength to upgrade the team and maintain the winning streak. If you roll while on a winning streak, players must upgrade their key champion to 3 stars, which is never an easy task.
You should roll if it doesn’t affect your economy
During the game of Teamfight Tactics, players often go through a phase of accumulating gold to reach the 50 gold mark as quickly as possible. During this phase, you will often find yourself with odd amounts of gold such as 27, 37, or 46 gold. At that point, a single roll is advisable to help players increase the strength of their team and avoid losing health. You might even buy strong champions and steer your gameplay if you are lucky enough.

Of course, players should not “all-in” their gold too early. You need to stop rolling if it affects your economy and income thresholds. For example, with 37 gold, you should only roll once to ensure that in the next round, whether you win or lose, you still have over 40 gold. If you are too greedy in rolling champions early, the consequence is that you do not upgrade your team but lose a lot of gold instead.
You should roll when you have many potential power milestones to achieve
In the early and mid-game stages, when the team is not yet complete, you will have many opportunities to reach various power milestones. To recognize your opportunities, you need to observe the units you have and aim for goals like upgrading a pair of champions to 2 stars, buying strong independent units, or adding more effects to your team. If you notice you have more than 4 opportunities to upgrade your team, you should roll and create advantages over your opponents.
For example, in the image below, you have 3 pairs of champions that can be upgraded, including Nasus, Yasuo, and Irelia. You can also gain the Mystic effect with Janna if you own Yuumi, Neeko, Shen, or buy strong individual units like Kayle, Aatrox, Sejuani. Players will have 9 opportunities to upgrade their team, which is a large number, so rolling is necessary.

Players should also remember that after achieving a team upgrade goal, you should stop rolling. Continuing with the above example, if you buy Yuumi, then options like Kayle, Aatrox, Sejuani will be eliminated as they are not stronger than the Mystic effect. You also should not play Neeko, Nasus anymore as these units are weaker than Yuumi. Therefore, you should stop rolling as the opportunities to upgrade your team have significantly decreased.
