When trying to capture a Pokémon, there are four different types of Throw bonuses that you can get: Normal (When the Poké Ball reaches the gray circle, but not the red one), Nice (when the Poké Ball reaches the red circle during 100% to 50% of the circle's size), Great (when the Poké Ball reaches the red circle during 49% to 25% of its size), and Excellent (the Poké Ball reaches the target when the red circle's size is below 25% of its size). An excellent Throw will increase your chances of catching a Pokémon.
How to throw excellent in Pokemon Go
● When catching a Pokémon, touch and hold the poké ball until the target circle appears
● Wait for the target circle (the red one) to reach the right size for an excellent Throw, and stop holding the poké ball
● Hold the Poké Ball again, during the Pokémon's attack
● Throw the poké ball exactly when the Pokémon finishes the attack movement