I think Ferrer has played most of this season on his peak level and I don't know how much better a season he could anymore have. If we look at this season, there wasn't many matches where he underperfomed. He could've beaten Rafa in Barcelona F and Rome SF, and maybe Murray in Wimby QF, where he could've then get even to final.
But where are his limits? In slams, SFs and QFs are his normal level, maybe earlier rounds in Wimbledon. A slam final? Possible but needs a wonder to avoid Fed/Nole/Rafa in QF and SF. Wimby this year was maybe his best chance for a slam final, Murray in QF and Tsonga in SF were players he could have beaten. Well what about a slam title? That should be a crazy slam. It should be something like this; Rafa can't play RG and in SF Ferru beats DelPo, who beat Nole in QF. And in final he'd beat Berdych who beat Federer in his SF. Not unrealistic but veeery unlikely.
But how well can he do in the Masters Series? For sure he'll reach semis in TMSs, but to get into final, it should almost be a weak TMS, like Monte Carlo, Shanghai, and Paris often are. What about winning another TMS title? As long as he avoids Fed/Nole/Rafa in final, he can do it.
And how well can he do in WTF? On proper, fast, indoor court, all WTF players have a chance to beat him. And on slow HC, he can well get to semis. But if others don't play their best tennis, he can even win WTF, even on fast indoor HC, he has already one WTF final. But to win WTF, he should avoid Fed/Nole in the final, Rafa as a weak indoor player could be enough vulnerable so that Ferru could beat him.
But in general, how much can Ferrer still achieve? My answer is as much as one can achieve without facing a player of Fed's, Nole's, or Rafa's calibre. And Murray isn't one of those players, Ferrer can beat Murray, like we saw at RG.
Another thing is how many years Ferrer has left on this level. He's 30 now, so I'd say 2 or 3 at maximum. And this season was so good for him that I think this will remain as his best season ever. That's why I'd love him to win WTF to get his career-best year-end ranking of #4.
The only place Ferrer has any sort of advantage over Murray is clay. And tbh, I don't see that lasting much longer.
On every other surface Murray will bitchslap him.
Look at all their head to head except clay. Their last 11 matches, Andy has spanked him 6 times.
Ferrer has won 5 times.. 4 of those on clay.
Their most recent meetings 2011/2012, of the 6 matches, Andy has won 4 times.
Conclusively, the only hope Ferrer has is that he plays Murray on clay, any other surface and he will most likely lose.
Now skewer the stats and compare Ferrer to Djokovic, they have only met on clay 4 times. And Ferrer has taken 3 matches.
I think it's obvious he's a clay specialist, which is why he schedules most his matches on clay.
The only players of the top 4 that Ferrer doesn't have a good match up against is Rafa and Roger...And that is pretty self explanatory.
In other words, Ferrer's best chance to do anything significant in a grandslam is the FO... And unless Roger/Rafa combust, he's not winning any slams anytime soon.
That's what happens when you're an all clay mug like Almugro.