SF is is a sharp tip with a flattened end. As a result, SF displays a combination of Attack qualities and Stamina qualities, moving in a semi-aggressive pattern. Because of this however, the two attributes are compromised, culminating in an average performance in both categories.
It produces a movement pattern that, while is aggressive, is much slower than any Flat Performance Tip. The increased friction with the stadium floor due to the wider tip both increases its Defense and Stamina in comparison to a bottom similar to S or ES. However, it is in absolutely no competition with bottoms similar to WD for Stamina or RS for Defense.
Semi Flat is meant to be used in Balance type Beyblades, and as mentioned, exhibits aspects of several types, however it excels in none and thus is essentially useless.
SF's only mildly effective use is in Destabilizer customs where the low Spin Track used along with the balance of qualities allows the custom to destabilize the opposing Beyblade.
Unless used in a destabilizer combination, SF is highly outclassed.
Attack: 3 - Defense: 2 - Stamina: 2