It's way too early to judge any of the permanent January transfers.
The window barely ended over a month ago. Teams are spending tens of millions of dollars on transfer fees, and they're signing their players to long-term contracts. On top of all of that, it's really hard for anyone to switch teams and cities and maybe even countries midseason and immediately play your best. It's going to be a long time until we can be confident whether too many of these moves have failed or succeeded.
At the same time, these early months -- and these first 10 or so games -- still count. If a player doesn't play. or plays poorly, you don't get to add that time back onto the end of his contract. Barring an injury crisis or an unlikely shot at a title or a European place, every transfer should be a long-term move. But ideally, every transfer pays off in the short-term, too. And if it happens to be a loan move? Well, there's a short term, an even shorter term, and that's it.
So, have any January transfers hit the ground running? I've picked out the 15 biggest January transfers in Europe (as determined by the fee and the player's crowdsourced market value on the site Transfermarkt and ranked them based on the immediate impact each player has had for his new club.
All stats reference domestic play only.
