Well. Assuming Fed doesn't up and surprise us and retire after the US Open, he should be a lock for the YEC. (With Laver cup and a 10 year deal with Uniqlo and feeling good and having just made the Wimbledon final, I'd be shocked if he retired this year and honestly, he'd be an idiot to retire this year. Sure. Maybe you want to go out on top or at least before you're struggling. But there's no reason for him to do that yet. Laver Cup may actually be the biggest reason for him though. He's just getting it off the ground.) Djokovic and Nadal are locked for the YEC now. Fed isn't technically yet. But it's gonna be impossible for 6 other players to pass him. By the end of the US Open he should have it all locked up with just some QF runs at Cincy and the US Open.
And he may not be able to get the #2 seed before the US Open, though there's a good chance if Nadal doesn't defend Canada. But he could get it after the US Open if Rafa doesn't win it. Because he lost early last year he can add a fair amount of points. But, could also lose it even if he gets it, because I think he has more to defend than Rafa going forward. Or at least after the US Open. Hasn't played Canada in a few years so an appearance there would be helpful, but don't count on it. But has the final to defend in Cincy and semis in Shanghai and Paris and the Basel title. So not without points to defend of his own. Needs a semi at the US Open. Of course he'd love to win it a 6th time.
Nishikori within 5 points of Tsitsipas. Medvedev into the top 10. Falls to 8 in the race. Was at 6. Is this the first time or did he do it once before this? I can't remember. Tough loss to Goffin in the 3rd or 4th round. Would have been a tougher test for Djokovic you feel like. Still. Don't think he could have pulled off an upset. Irrelevant speculation at this point.
RBA into the top 8 of the YEC race. 13 in the actual rankings. With DelPo still ahead of him. So should have a 12 seed or better at the US Open. Hard courts actually his best surface. Should feel very confident after Wimbledon. And didn't play Cincy or Canada because of injury last year. And lost in the first round of the US Open. So zero points to defend over the next month and half. Probably should be top 10 by the end of the US Open.
Thiem and Zverev hold at 4 and 5. But Thiem already at 4 for the YEC race and Zverev at 10. Big difference in points from this year for them. Thiem has like 1000 points to defend the rest of the year. Zverev has about 2400 or 2500. Huge for Thiem to defend his RG final from last year this year. Most importantly for Thiem, if he can get through other young players he may have to face early, he can't face a big 3 opponent until the semis. So an epic like his match with Nadal last year in the ... 4th round??? can't derail him. But. Plenty of talent in those ranked below him.
Fognini at 9 in the rankings and 9 in the YEC race. Always useless on grass but did great to avoid the Tiafoe upset and prove everyone calling it as almost guaranteed wrong. And made the... third round here. Solidish. Would just be huge for him to build on Monte Carlo enough to make the YEC. Hasn't been horrible on hard courts. He'd love to do well enough before the US Open to get a top 8 seed and avoid the top 4 til the quarters. Still. He's only got like 1 4th round there I think.
At this point, I'd bet on the current top 4 being in the YEC. Tsitsipas. Medvedev. Nishikori. RBA. Zverev always capable of finding "it" again and making a run for it. Fognini in the hunt and could get it. But Zverev seems all out of sorts. And Fognini is unreliable. RBA with the AO QF and this SF here has really set himself apart since his return from injury. Nishikori just continuing to look solid. Second best. Second tier. But solid. Surprisingly poor clay season or he'd be in a more confident position to make the YEC. If he's healthy though, he's always a threat.