# Most expensive Premier League football transfer of all time: Rio Ferdinand

No, this post isn’t 15 years late, Rio Ferdinand really did cost “more” than Paul Pogba…

Okay, clearly Ferdinand (£39.1M: Leeds – Man Utd, 2002) did not actually cost more than Paul Pogba (£89.25M: Juventus – Man Utd, 2016). Well at least not in absolute terms.

We all know that every season values of transfers are inflating, not just due to inflation in the currency (the 100 biggest transfer fees adjusted for inflation can be found here), but also because of the increasing amount of money in football.

Using the fantastic data at transfermarkt.co.uk we can get all of the historic transfer values, and plot them over time, along with the annual mean and standard deviation (transfers whose values were unknown are excluded):

We can see the steady increase in the mean cost of transfers, and Paul Pogba’s transfer is very clearly the largest value. However, this large inflation in costs (which has been recently driven by the huge increase in TV revenue) potentially obscures the true most expensive transfers. As such, if I standardize the transfers using a classic Z-score:
$z = \frac{x-\mu}{\sigma}$ where $$x$$ is the raw score, $$\mu$$ the mean, $$\sigma$$ the standard deviation and $$z$$ the resulting standardized value. And then map that $$z$$ value to today’s money (by multiplying by this years $$\sigma$$ and adding this years $$\mu$$) then the plot looks rather different:

Now we can see that the most expensive transfers in history (after normalization) are:

1. Ferdinand, (2002: £39.1M,  2016: £90.67)
2. Pogba, (2016: £89.25M)
3. Shevchenko, (2006: £36.81M, 2016: £88.97)

So there you go.

Edit: it was pointed out to me on Twitter that Paul Tomkins has performed similar, but mathematically different, analysis, with broadly the same results. You can check out his article here.

This entry was posted in Football, Mathematics and tagged , , , . Bookmark the permalink.