I saw a guy with 948 level in the game. I've been playing for more than 500 hours with average kills 25 and still lvl 218 ?!?!?
How tf he reached that level?

i would guess he played XP Bot Lobbys

Easiest way to explain it ... very few people actually play just 1-2 games for years. It's as shocking as seeing someone with 10k+ hours in an old game. And sometimes, they just play normally too (Rare). If you look at the time, they might be playing 6 hours per day. Plus, during the game's early days, they might've just been AFK farming(Fixed), which would make the actual playtime per day decrease by a lot.

Well im #55 world in Total Score (about 47mio) but just #650 with my rank (895)... at 1250 hours playtime now (about 4,5 hours per day since release).
As far as I'm informed the total score is the real total score you have reached in your matches without any bonus scores, but bonus scores count towards rank.
Highest ranked player is "Grenades" (check him on tracker.gg), his rank is about 8500 (he abused an idle-bug, has just 2mio total score more than me).

I've been thinking for a while that the system probably excludes bot matches now. As for Casual Breakthrough, I'm not really sure it still counts?.

I've been thinking for a while that the system probably excludes bot matches now. As for Casual Breakthrough, I'm not really sure it still counts?.
I think they removed Bot-Farm kills (those explicit bot-only servers in the first 1-2 weeks after release) but not sure if they also removed score.
"Normal" Bot Kills (in casual gamemodes and normal matchmaking games) still count towards your total kills today, but you have dedicated stat for player-kills (ingame and also on tracker.gg).

Well im #55 world in Total Score (about 47mio) but just #650 with my rank (895)... at 1250 hours playtime now (about 4,5 hours per day since release).
As far as I'm informed the total score is the real total score you have reached in your matches without any bonus scores, but bonus scores count towards rank.
Highest ranked player is "Grenades" (check him on tracker.gg), his rank is about 8500 (he abused an idle-bug, has just 2mio total score more than me).
Just played a round with Grenades, dudes legit other than his XP

Yes, he still is a good player. Didn't question that ;)
I held the first worldrank in Score per Minute in BF3 for about 6 months (with ribbons/medals + double XP with about 5200 SPM after the needed 2h playtime after SPM reset), so how could I complain about abusing game mechanics stupidly implemented by DICE xD
But still had real 1200 SPM on Metro, before they started their doubleXP Weekends + stats-reset garbage, so I've already been in the top50 before that time.

I've been thinking for a while that the system probably excludes bot matches now. As for Casual Breakthrough, I'm not really sure it still counts?.
I think they removed Bot-Farm kills (those explicit bot-only servers in the first 1-2 weeks after release) but not sure if they also removed score.
"Normal" Bot Kills (in casual gamemodes and normal matchmaking games) still count towards your total kills today, but you have dedicated stat for player-kills (ingame and also on tracker.gg).
I remember there was a time when I could check bot kills, so it's probably been removed, that probably includes matchs and score that currently only give match completion XP too. Cuz I feel like my early stats/playtime got removed as well. But for tracker.gg, I don't know at all, but I also think it's pulled from EA's current data, which should have already been removed.

Probably portal bot lobbies and exp boosters
While bot kills have been removed from your stats and K/D, all of the levels you got with bot farming didn't get removed. That's my understanding at least

Honestly, probably an internet cafe account. Played 24/7 almost. Cheaeters use them all the time. Russians are famous for it.

it's players who exploited the bot farm portal lobbies that were abused near launch. Chances that it's a cheater is extremely slim. As mentioned above, bot kills do not contribute to any player stat outside of unlocking gear and player level.

open your eyes and see the world, there has already been a maxed out lvl 9999 account, through portal xp farming of course.
and level that passes 1 hundred or 2 means nothing in battlefield, just a fking number.

Not related but you got a very cool job

Not related but you got a very cool job
I have to check that out after your comment, haha.

Not related but you got a very cool job
Thank you, brother.