Thanks to wonderful researches at Gamepress, we are finally aware of how and how much Berries, Pokeballs, Throws and Medals influence our chance to successfully capture a Pokemon. This page is a simplified version of the original Gamepress research efforts, intended for quick reference.
Chance to catch a Pokemon is always less than 100% and is equals to:
Multipliers = Ball ∗ Curve ∗ Berry ∗ Throw ∗ Medal and you don’t have any influence on BCR (Base Capture Rate) and CPM (CP Multiplier), so don’t worry about it.
Ball influence on capture rate
Sorry to disappoint you, but rumors like “Great ball is good for evolutions” and “Ultra ball is only for Dragonite” are simply not true. Better ball type increases your capture chance no matter what Pokemon you’re catching. The increase is linear, but quite substantial.
According to research the Curveball is one of the most important aspects of catching Pokemon, as it increases the multipliers chance to capture a Pokemon by 1.7, which is more than using an Ultra ball over a Pokeball!
Of course, the way you hit a Pokemon during capture encounter also matters. Great and Excellent have big benefits compared to Nice and no bonus at all. Always aim for the circle!
Moving along, using a Razzberry also provides you with a hefty bonus increase. Using a Berry is essentially equivalent to using a Ultra ball over a Poke ball. The Razzberry bonus is 1.5 in the Multiplier formula.
Type Medal Bonus
The Medal bonus is finally verified and transparent. The increase is flat, you don’t have to do anything to activate it, it’s always activated when catching a Pokemon. It’s not efficient like using a Berry or switching to a Curved Ultra Ball, but it is passive, like a passive buff.
For dual types, the bonus is an average of the two medals.