I'm surprised you're taking issue with the LostGen moniker,
@herios. Remember that no player born in 1989 or later has won a Slam - that is, players turning 29 and younger this year. That is unheard of in Open Era history - probably all of tennis history. Now clearly it is only inevitable that someone starts winning Slams, but there's a reasonable chance that no player born between 1989 and 1992 wins a Slam. Ever.
Here's a list of the best players by year (with age they turn in 2018 in parentheses for the mathematically challenged), with comments on each (I got carried away):
1989 (29):
Kei Nishikori - For a short while there he was the best bet to be the first Slam winner of this generation, with a more balanced skillset than Milos and without the wussiness of Grigor. But I don't see it anymore...
maybe a Masters/WTF, but he hasn't yet returned to peak form and the clock is ticking.
Others - Paire, Klizan, Sousa, Steve Johnson, Bedene, Donald Young...None of these guys have a snowball's chance in hell of winning a big title. A weak year of talent.
1990 (28):
Milos Raonic - I suppose he will remain a darkhorse candidate to win Wimbledon, and could do an Ivanisevic, but I don't see him getting by the Big Four, and there are better NextGenners coming up. He'll have to thread the needle with a huge dose of luck or a Cilicesque tournament.
David Goffin - Goffin is an interesting one. He's a bit Ferreresque in that he's got a solid level, but just doesn't have the A-game needed to beat the elites. But he's also had some strong tournaments (e.g. 2017 WTF) and is in a similar category as Kei and Milos in that he could win a Slam if the stars align just right.
Others - Delbonis, Pospisil, Janowicz, Donskoy, Lajovic, etc....See 1989's Others category. Same deal.
1991 (27):
Grigor Dimitrov - There will always be 2017. Seriously, though, he finally broke through and won not one but two big titles, and the WTF to boot. But 2018 looks more like his pre-2017 form. That said, he is only 27 and leads the pack of this generation.
Pablo Carreno Busta - After stagnating for a few years he's come along nicely over the last couple years, even reaching the top 10. But it is hard to imagine him being anything more than a #10-20 type. I consider him a darkhorse for a Masters.
Others - Kuznetsov? Nothing to see here.
1992 (26):
Jack Sock - So much for Skip's assertion that Sock was breaking into elite status. He's a solid player, but I don't even see him as a second tier type (#5-10), more of a good third tier who happened to opportunistically win a Masters. I don't see him seriously competing for a Slam.
Diego Schwartzman - Everyone loves little Diego, but he's kind of a Ferrer Lite...hopefully he can sneak in a Masters, but seems like another third tier ATP 250/500 type.
Bernard Tomic - Should we laugh or cry? Bernard is somewhat tragic. He really belongs in the "Others" category. I'm fairly certain he'll never win much, and would be lucky to sneak in a 250 or 500. In fact, I wouldn't be surprised to see him retire before he's 30.
Others - Kudla, Harrison, Dzumhur, Cecchinato - The latter two could surprise, especially Cecchinato with his nice form at Roland Garros. But no Slam winners here.
1993 (25):
Dominic Thiem - This was the guy who was supposed to take the Clay Crown from Rafa, right? Probably not. Rather, he seems to be bookending Rafa's career with Coria: a very good also ran clay courter who can't compete with the King. Still, he's young enough that he should have some good years after Rafa starts declining, so he's a good candidate to win RG. Nothing else, though. I suppose his nightmare scenario is that Rafa hangs in for another few years, and then some NextGenner emerges as being very good on clay. So while he's got a longish window, it won't last forever.
Others - Vesely, etc...Another weak year.
1994 (24):
Lucas Pouille - Another third tier type. Pouille might dip into the top 10 for spells, ala Goffin and Busta, but like those two he won't be a regular. As a #10-20 type, he'll win his share of 250s and 500s, but he's a darkhorse at best for a Masters.
Others - Jordan Thompson, etc...Another weak group.
1995 (23):
Nick Kyrgios - Angry Nick remains one of the most interesting players to watch on tour. But whereas a couple years ago he looked like he was on the verge of breaking out in a big way, he took a step back last year and has struggled with injury this year. Still, he's so talented that it is hard imagining not winning multiple Masters and even a Slam or two. He's the biggest wildcard on this list.
Kyle Edmund - I'm reminded of Sock in more ways than one. Edmund's breakout might be a bit of a mirage. Yes, he took a step forward, but I think at best he's a "tier 2.5" player. But we'll see.
Others - Nishioka, Djere, Marterer, Jarry, etc...Not much to talk about.
OK, I'll leave it there for now and maybe cover the next group in a later post. Things start getting more interesting in 1996, once we get into the heart of NextGen. As far as definitions go, I generally consider 1989-93 to be LostGen and 1994-98 to be NextGen, but we don't need to rigidly adhere to five-year groupings. Either way, 1994 seems transitional, and 1995-1999 seems to be NextGen, with 2000 being whatever will come next. Just to preview:
1996 (22): Hyeon Chung, Karen Khachanov, Borna Coric, Daniil Medvedev, Thanasi Kokkinakis, Jared Donaldson, etc
1997 (21): Alex Zverev, Andrey Rublev, Taylor Fritz, Jaume Munar, Reilly Opelka, Alexander Bublik, etc
1998 (20): Stefanos Tsitsipas, Francis Tiafoe, Casper Ruud, Michael Mmoh, Stefan Kozlov, Duck Hee Lee, etc
1999 (19): Denis Shapovalov, Alex de Minaur, Corentin Moutet, Miomir Kecmanovic, etc
2000 (18): Felix Auger Aliassime, Nicola Kuhn, Rudolf Molleker, etc
There are now players born in 2001 in the top 1000, but they don't really bear mentioning yet.