In recent years there has been an increase in transformative deals being negotiated between publishers and academic institutions. This is in response to a combination of factors, including the considerable focus on open access policies and the desire to make the transition to open access as seamless as possible for researchers. Publisher negotiations in the United Kingdom have been supported by Jisc, a UK agency focused on tertiary education, research, and innovation (Vernon, 2022), however institutions can individually negotiate with a publisher where they feel necessary. Quantifying how negotiation outcomes could impact the institution can empower library staff to confidently negotiate towards a transformative agreement. Data is powerful, and the data exchanged between institutions and publishers is ever growing - such as publishing quantities, read/usage, and financial data, and these can be assessed over time, against one another, or in comparison to other publishers. This paper documents the journey of the author as the data analyst at the University of Cambridge library, who was responsible for analysing the data relationship between the institution and the publisher Springer Nature as part of the 2022/23 negotiations.