Derby County paid £6m for Bobby Clark this summer, but he is not just proving to be an asset on the pitch as latest figures show

Derby County midfielder Bobby Clark's transfer value has further increased, according to the latest revised figures from the CIES Football Observatory. In its latest analysis of estimated transfer values in world football, the Observatory has calculated the most valuable players at each club.

CIES have determined that Clark is Derby's most prized asset and, back in September, assessed he was worth between £9m and £11m - around £3m to £5m more than the £6m fee Derby reportedly paid when they signed him from RB Salzburg this summer.

But in their regularly updated figures, CIES claims that Clark's fair market value is now between £13m and £15m, which is another increase and more than double what they forked out for him.

The former Liverpool midfielder has been one of the standout performers in what has been a tricky season so far, having grabbed three goals and registered two assists since the Championship season began. Clark scored against Birmingham City, Cardiff and Sheffield United, but also laid on goals for Sam Szmodics at Portsmouth and Carlton Morris, also against Cardiff, in a 2-2 draw.

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Derby boss John Eustace had challenged the midfielder to improve his numbers in the final third, having scored three goals and created another three in the second tier last season when he spent the season on loan.

His form persuaded Derby to make his move permanent in the summer, and he was the highest outlay for Derby in a summer that also saw them spend £4m on Crystal Palace midfielder David Ozoh, who arrived on deadline day.

Clark's valuation takes into account his age profile, contract and who could potentially sign him in the future. It's a big boost for the club's owner, David Clowes, in the era of profit and sustainability rules, as it is likely Clark will be sold on, hopefully for a big profit, in the future.

CIES' verdict puts him mid-table in the list of the most valuable Championship players for each club. Wolves' Mateus Mane tops the list with an estimated transfer value of £39m. West Ham's Valentín Castellanos is second with a value of £37m while Middlesbrough's Will Lankshear has rocketed up the charts and is now third at £27m.

CIES have long studied data in football and are located in Neuchâtel, Switzerland. TIt was created in 2005 by Dr. Raffaele Poli and Dr. Loïc Ravenel. The CIES Football Observatory comprises five people: three researchers (Drs Raffaele Poli, Roger Besson and Loïc Ravenel), a business analyst (Arnaud Bertrand), and a collaborator responsible for data collection (Andrea Pessina).

The Observatory also benefits from the support of the staff of the Centre International d’Etude du Sport (CIES), an education and research centre to which it belongs.

Since its creation in 2005, the CIES Football Observatory research group has become a reference point in the demographic and economic study of the football players’ labour and transfer markets, the analysis of the clubs’ and players’ performance (technical, tactical, physical), as well as the scientific estimation of transfer values.

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