Accas are popular because the possible return is exciting. They are dangerous for the same reason. A sensible accumulator starts by asking whether each leg is worth including before the combined odds distract you.
Every leg needs a reason
Adding a weak leg to make the return bigger usually makes the bet worse. If a selection does not have its own evidence, it should not be rescued by the rest of the slip.
Probability falls quickly
Five selections that each have a 70% chance combine to about 16.8% before bookmaker margin. That does not mean the acca is bad, but it does mean the price has to compensate you for the combined risk.
Watch correlation
Some legs are connected. A team win, team goals and a striker shot line may all depend on the same match script. Correlation can be useful when priced correctly, but it can also create the illusion of diversification.
What Ressq is optimising for
Ressq's Acca Builder is designed to balance price, probability and evidence quality. The aim is not the longest possible odds. It is a slip where each leg has a clear reason to exist and the total risk is visible before you place anything.