Transfer rumours are hot and heavy on Monaco's Kylian Mbappé this week. Some might even call the speculation "furious". Manchester United have allegedly tossed £72M at Monaco. Real Madrid today are rumoured to be on course for an £85M move (which presumably means Benzema or Morata are leaving, and half the deal will be recouped through selling one of them).
Mbappé is 18 years old. He has also had a torrid - but somewhat lucky - season at Monaco this year. Today I want to briefly walk through his underlying numbers and discuss what valuation I would put on him in the transfer market.
Previously I helped on a couple of real world deals for high profile players that were negotiating new contracts, and this type of valuation process proved very valuable and lucrative there.
The Stats
Mbappé is already an outstanding scorer, and the fact that he's well-rounded and not just a poacher is hugely impressive. On the other hand, he's currently scored double his expected goals. If you think he's going to score a goal a game, you will likely be sorely disappointed.
However...
Half a goal a game of xG is excellent. Mbappé is already a significant outlier for players under 23 across Europe. Don't be disappointed he's not the greatest player in the world right now. Be very very excited that even without the overperformance, he's already one of the better scoring forwards in Europe at age 18.
The Eye Test
Mbappé plays in a good-but-not-great league, and he's shown the ability to terrorize some of the best defenses in the world in the Champions League. In the first 25 minutes against Juventus, he gave the entire Juve back line fits with pace, power, and movement.
Having watched quite a few Monaco CL and league matches this season, I can also tell you that Mbappé regularly produces exciting moments of skill that would be fantastic from a 25-year-old. The fact that he's out there doing it at 18 against grown men is staggering.
Oh... and he's So. Damned. Fast.
Valuation Discussion
Given what we know above, the question now becomes what value do you think Mbappé should have. Ignore for a second that we only have this one season of data. Assume Mbappé's baseline stats are rock solid, and we can expect him to produce .5 xG per90 for the next 7-10 years.
The value on that is at least £50M. Factor in the fact that he has a lightning first step, can dribble, and also knows to keep his head up for a pass and now we're past 60M.
Then there's another factor. What if Mbappé really is Thierry Henry Mark II? Or Ronaldo (either the Brazilian or Portuguese one)? He's still maturing, but player development is uncertain. Maybe right now is Mbappé's peak but - just maybe - his peak is legendary.
Well we know for a fact that Ronaldo and Messi and Henry in their prime would be valued somewhere between 150M and You Can't Buy This. Let's estimate an approximate fee in those situations to be £200M. Subtract the 60M mark we already have and you get £140M of "potential pricing."
The question then becomes what probability you assign to him reaching that legendary status.
Say your scouting group loves Mbappé as he is, but it's only 20% likely he'll become a Ballon D'or winner. The calculation is then 60M (actual) + 28M (legend potential) = 88M. If you are able to buy him for 88Mish, you are in good shape.
Now there are other factors at play that change the price equation, like Mbappé is SO YOUNG that even after a 5-year deal, he's still only going to be 23, meaning you might not need to spend another 100M then, so maybe that moves the price up.
But maybe you are really concerned that we only have one year of data for the kid, and Monaco are a bit weird and overperforming expected goals massively, and he's playing for a super team and...
Then maybe that increases your risk assessment and you drop the price you are willing to pay because of it.
This skill set from a fully grown player is rare. This skill set from an 18-year-old is absurd. Given the fact that Mbappé could produce .8 or .9 xGA a game for the next decade, it's not unreasonable to put a £100M tag on him right now. Preferably the base fee is a bit lower with huge add-ons, but unless there is a release clause in his contract, Monaco have a very strong hand to play in negotiations and can demand an awful lot of cash up front.
Anyway, I thought this case was really interesting to analyse through the context of how I would think about it inside of club recruitment. I hope you enjoyed it, and if you find yourself needing professional help in this area, get in touch.
Ted Knutson
ted@statsbomb.com
@mixedknuts