Magic Estimation is an estimation technique that is quick. It is especially useful to quickly estimate a large number of items.
The benefits of Magic Estimation are the speed (due to only non-verbal communication) and the subjectivity with which each team member can look at the process. Magic Estimation provides the Product Owner with a good overview of the degree of complexity of the Product Backlog entries and which still need to be broken down, so that they can delivered in a Sprint.
In the first step, everyone places the item to be estimated next to the number he thinks it belongs to. E.g. someone places a User Story next to the Planning Poker card "8", because he estimates that the story has a complexity of "8". If someone estimates differently, he moves the item to another Planning Poker card. Some items will stay where they initially have been placed. Some items will move around between estimates. The moderator keeps track of these items to discuss them in the second step. During the first step no one is allowed to speak.
In the second step the moderator goes through the cards that have moved back and forth between estimates. He asks the two people with the highest and the lowest estimate to explain their reasoning. Planning Poker can be used to estimate these items more precisely.
Affinity Estimating is variant of magic estimation. We start by reading out each User Story to the entire team. The moderator then asks to arrange the stories horizontally on a wall in order of size, without talking. The team places the largest stories on the left and the smallest stories on the right. This only takes a few minutes. The moderator then gives a final opportunity to make adjustments to the ordering, again without talking. The moderator then places the Planning Poker numbers above the list of stories. He asks the team to group the user stories around the nearest number.