There are two types of aiming........direct and indirect.
Direct aiming is when there is a direct path to the OB for the CB.
Indirect aiming is when there is not a direct path to the OB for the CB. Common example is having to send the CB to a rail first then the OB like can happen in safety play. Another is going CB rail first to pocket in order to get a better angle off the OB or go around a ball blocking the ball you want to pocket.
Any system that requires using parts of both the OB and CB for aiming is direct aiming, meaning it is limited when it comes to indirect aiming. Fractional is a example.
Any system that uses CB location on the table can be used for direct and indirect aiming as it doesn't depend on using parts of the OB for aiming, Ghostball.
Direct aiming is when there is a direct path to the OB for the CB.
Indirect aiming is when there is not a direct path to the OB for the CB. Common example is having to send the CB to a rail first then the OB like can happen in safety play. Another is going CB rail first to pocket in order to get a better angle off the OB or go around a ball blocking the ball you want to pocket.
Any system that requires using parts of both the OB and CB for aiming is direct aiming, meaning it is limited when it comes to indirect aiming. Fractional is a example.
Any system that uses CB location on the table can be used for direct and indirect aiming as it doesn't depend on using parts of the OB for aiming, Ghostball.