For Premier League era only (so from 92/93 onwards), Liverpool has 3rd best points tally after 19 games.
1 Man City 17/18 - 55 points (GD +48)
2 Chelsea 05/06 - 52 points (GD +32)
3 Liverpool 18/19 - 51 points (GD +36)
In the same period, 44 points (or more) has been achieved 20 times within the first 19 games. This season is the only time that 3 teams have achieved it (Liverpool, Spurs, Man City).
The only other times in which 2 teams have had at least 44 points at this stage are:
2003/04 - MUN 46 points and ARS 45 points
2011/12 - MCI and MUN both 45 points
2007/08 - MUN 45 points and ARS 44 points
1999/00 - MUN 45 points and LEE 44 points
So, for first 19 games, as well as having the 3rd best total for top of the league, it has the highest ever totals for second and third positions respectively.
The best ever 19 game start (in premier league era) by a team which did not go on to win the league was in 2003/04. Man United had 46 points. As noted above, they were 1 point ahead of eventual winners (Arsenal) who finished the season unbeaten, and with 90 points. Put another way, Arsenal managed to get exactly 45 points in each half season, whereas Man United fell away dramatically to add just another 29 points from their remaining 19 games.
By way of comparison, Man City's last 3 half seasons have yielded an aggregate of 144 points, at an average of 48 points per half season (ie per 19 games).
So if MCI do no better than match their own average (and they might do better, of course) then they will end up on 92 points. That would still be the fourth best ever tally after 38 games (following MCI's 100 points last year, CHE's 95 points in 04/05, and CHE's 93 points in 16/17).
There's gonna be a lot more twist and turns, of course, but it's been a great Xmas so far!!!