An incredibly shrewd move. We have effectively swapped an injury-prone demotivated experienced Koscielny for a younger (albeit one year) experienced winner in Luiz. Improves our build-up, mentality and morale as well. Length of the contract is a bonus too. Weakens Chelsea (our main top 4 rivals) considerably. This is evidently one of the benefits of us becoming pally again with the likes of Kia Joorabchian.