I do feel the need to point out that Tiki-Taka is not based around possession retention. That was a philosophy throughout the Barcelona system that was employed alongside Tiki-Taka.
Tiki-Taka litterally translates to "Tip-Tap" it, based around quick direct direct passes with exceptionally fluid movement off the ball. It's similar to the system Brendan Rodgers employed at Swansea but when you have an ideology of possession instilled by the Barcelona coaching staff, you end up with a team that moves the ball quickly and holds onto it.
For me, what Barcelona done was incorporating possession retention into a Tiki-Taka system but that was only possible due to their exceptional technical ability. It was the perfect storm and I don't think we'll see it again.