What‘s Gilbert smoking? Federer was better in 2015 than in 2017 and dominated the tour except for a BOATing Djokovic who stood in his way. Federer beat Djokovic 3 times including twice in 2015 finals while Novak was at his best winning 3/4 Slams on the way to his Novak Slam. Djokovic was 82-6 in 2015 with 3 losses to Federer while Federer was 63-11 with 5 losses to Novak.
Federer has had more dominant seasons when he was younger, but 2015 was the highest level I’ve seen Federer play at Indian Wells over the years - better than ever before or ever since to my subjective eyes. I’m in good company with this opinion as Federer himself said this at Cincinnati in 2015.
Firstly fed was significantly better in IW 17 than in IW 15. He was also significantly better in IW 12 than in IW15. Heck, he was better in IW 14 than in IW 15. and that's just this decade. IW 15 is like maybe fed's 8th best IW (after IW 04/05/06/11/12/14/17).
Secondly, fed's win over nadal at AO 17 was a tougher win in a slam than any opponent he beat in 15 in slams, even Wawa in AO 17 for that matter.
He was 54-5 in 2017 even with injury marred loss to Z.
going 4-0 vs 17 nadal, including AO win in 5 sets and thoroughly dominant in next 3 wins (not broken, no set lost) is significantly more impressive than losing in 4 each at Wim/USO to 15 djokovic; doing well in RR match but mediocre in the final at the YEC. dubai is still a 500, fed was good/clutch, but still a lesser win than the 3 wins over nadal in 17 in masters. Only Cincy 15 vs djokovic was real impressive&counted for quite a bit.
Federer in 15 lost to Seppi at the AO. He won AO in 17 facing a tough draw.
a little better in Wim in 17 than in 15.
better in USO 15 than in USO 17 due to injury just prior to USO 17
he made only 3 masters finals in 15 (playing 6 of them). in 17, he played 4 masters, making final in all of them
better in YEC in 15 than in 17
so better in slams in 17, better in masters in 17, better in YEC in 15
IW 17 was basically similar form to CIncy 15.