The UEFA Champions League is back, but not how we've ever seen it before. Some changes are simple, others are more complicated, and a few might seem a bit of a mystery until we get to the knockout rounds in February.

So, what is the new format? How could the draw play out? When do we get to know the fixtures?

We've mapped it all out ahead of the draw, which takes place at noon ET / 5 p.m. BST / 6 p.m. CET on Thursday.

How does the mock draw work?

The Champions League draw is now all about creating each team's individual fixture list. We've selected six top clubs and picked out their opponents, based on the constraints of the draw and the pots.

With all 36 clubs in one league table, the competition is going to look very different. Will the league phase be competitive? We've crunched the numbers to produce a league table after seven of eight rounds to show how much movement there could be on the eighth and final matchday, which sees all 18 matches kick off at the same time.

The final table automatically creates the possible paths through the knockout rounds, and we'll show how that works too.

The mock draw, schedule, results and table are purely illustrative and shouldn't be taken as a prediction of what's actually going to happen.

What is the new Champions League format?

Let's start with the basics. This season marks the first time in 21 years that we've had a format change for Europe's top club competition. For the previous 21 seasons, 32 teams qualified and were drawn into eight groups of four. The top two teams went through to the round of 16, with third dropping into the UEFA Cup/Europa League and fourth eliminated from Europe.

We now have 36 teams, but they won't be drawn into groups. Instead, we have the Champions League "league phase."

So, how does it work?

Teams in positions 25 to 36 are eliminated in January
The 16 teams in positions 9 through to 24 play in the knockout phase playoffs, in February, to earn a place in the round of 16
The top eight go straight through to the round of 16, played in March

Also new for this year: it's no longer possible to drop into the Europa League from the Champions League (or into the UEFA Conference League from the UEFA Europa League)., Once you're out, you're out.

From the knockout phase playoffs onwards, the competition retains its two-legged format through to the semifinals, with a traditional one-legged final, but with limited draws -- more on that later.

What do the Champions League draw pots look like?

Not much has changed in how the draw looks on paper, as there are still four pots of teams that contain nine clubs rather than eight. But there are still some notable adjustments given the expanded field.

How seeding has changed

Pot 1 used to house the holders of the Champions League and Europa League, plus the champions of the top six domestic leagues. Pots 2 through 4 would then be ordered by strength based on UEFA's club coefficient, which ranks clubs on performance in Europe over the previous five seasons.

Now only the Champions League titleholders will be automatically in Pot 1, all other positions will be on the UEFA club coefficient.

However, the new Champions League format means the pots themselves have less relevance, as teams will be drawn to play two clubs from their own pot. Under the old system, being in Pot 1 could give you a more generous draw, as you couldn't play a team from your own pot in the group phase.

For the purposes of the mock we've used the seven highest-ranked clubs (by UEFA coefficient) from each of the playoff round ties being played this week.

POT 3: Slavia Prague, Dinamo Zagreb, FC Salzburg, Red Star Belgrade, Young Boys

POT 4: Slovan Bratislava, Sparta Prague

The mock will be updated through the final qualifying round this week.

OK, so how does the draw work?

Rather than placing teams into groups, the draw now creates the fixtures. Each club will play eight games, with two opponents drawn from each of the four pots. One match from each pot will be at home, and the other away.

There are two main principles this season:

No club can play another team from their own league (for example, Arsenal cannot play Aston Villa).
A club can play no more than two teams from one country (if Arsenal draw Bayern Munich and Borussia Dortmund, they cannot then play VfB Stuttgart)

The draw ceremony will be noticeably different, too. In previous seasons, the fates of all 32 teams would be decided by a manual draw, with balls and pots for teams and groups, by a parade of former Champions League players. But the new format is so complicated that it would take over three hours and require 1,296 balls.

Here's how it now works:

A team will be drawn by an ex-player on stage (starting with Pot 1 and ending with Pot 4)
A computer will randomly select that club's eight opponents (subject to the constraints of the draw), and determine which match is played home or away.

Pot position might not be so crucial, but they still have relevance as each will contain a range of quality. The distribution of home and away games will also be important given the range of possible opponents for each club.

Here's how our draw played out for six selected teams.

In this hypothetical, Arsenal arguably have the best outcome from the possible Pot 1 opponents, facing RB Leipzig and Dortmund, but get a tougher assignment from Pot 2 with matches against Atalanta and Atlético Madrid.

Liverpool would be satisfied with their fixture list too, with the game against Real Madrid being scheduled for Anfield and Club Brugge as an opponent from Pot 2.

Barcelona get the toughest draw in this simulation, facing the champions of England and Germany plus Bayern, Milan and then, from Pot 4, Aston Villa.

Will the league phase be exciting?

There have been some comments that the league phase could be quite dull, that there'll be little to play for as the top eight clubs will qualify directly to the round of 16, and the next 16 will all go into the knockout phase playoffs. We're only going to lose 12 teams out of 36 at the end of the league phase.

The league table we have put together after seven rounds shows there should still be lots at stake heading into the final matchday. With only 24 points available to each team, the table won't be anywhere near as spread out as a domestic league; indeed, it's possible for a club to move seven or even eight places on matchday eight.

After seven rounds:

Two clubs were guaranteed top eight
17 clubs were in contention for the six remaining top eight spots
17 clubs were guaranteed minimum of a place in the knockout phase playoffs
No club was completely locked in the knockout phase playoffs
14 clubs were vying for the last five spots (20th to 24th) in the knockout phase playoffs
Only three clubs (34th to 36th) were already eliminated

Taking into account the number of matches and teams involved, 15 points will usually be enough to finish in the top eight, with nine for a place in the top 24. There could be seasons where more points are required, and indeed in our mock some did miss out on 15 points due to inferior goal difference.

To try to make every game important through to the final day, UEFA has linked a club's final league position to the knockout bracket, meaning where a club finishes affects their path. The higher you are placed, the easier the route (based on league ranking) through to the final. For instance, the teams who finish in first and second cannot play each other until the final; those who are third and fourth would avoid first and second until the semifinals, and so on (check out the knockout round chart to see how this falls into place.)

The question is how much those clubs in the middle section will really care about their final placing. Of course, if they outperform their UEFA coefficient ranking they might get a more favourable route to go deeper into the tournament, but even that is reliant on the relative performance of others (e.g. they might play a top team who has had a below-par league phase.)

In our table after seven rounds, only two clubs -- Real Madrid and Manchester City in first and second -- were guaranteed their place in the round of 16, while the bottom three were out.

And that brings us to the mammoth final matchday, when all 18 matches will be played simultaneously -- like the last day of the Premier League season.

Positions could be changing every time a goal goes in, from those key spots near the top of the league to the clubs trying to hang onto, or force their way into the top 24.

Here's our sample (not to be viewed as predictive) results for matchday eight, and how they affected the final table.

Two clubs lost their places in the top eight, with Liverpool's defeat at Atalanta seeing them fall four places into 11th. Inter also missed out after drawing with Sturm Graz, dropping one place to ninth.

The beneficiaries were Bayern Munich and AC Milan, with wins taking them into seventh and eighth. Despite getting 15 points, Inter and Aston Villa missed out on the top eight on goal difference.

Positional changes could be more pronounced in the battle to sneak into the top 24 -- as fewer teams are likely be winning matches. Indeed, victories for Atalanta, PSV Eindhoven at home to Slavia Prague, and Girona against PSG saw all three climb five places and make the knockout phase playoffs, finishing 21st, 23rd and 24th respectively. Brest, Celtic and Young Boys all fell out of the top 24 with final-day defeats.

When will the games be played?

UEFA plans to publish the fixture list on Saturday, Aug. 31. Clubs cannot play teams from any one pot in consecutive matchdays -- from our mock, Arsenal couldn't play Pot 1 teams RB Leipzig on matchday three and Dortmund on matchday four.

Kick-off times will remain the same, with two matches at 5.45 p.m. UK / 12.45 p.m. ET and the rest at 8 p.m. UK / 3 p.m. ET. However, on the final day of the league phase all 18 matches will begin at 8 p.m. BST / 3 p.m. ET.

UEFA has expanded the footprint of the European calendar to cover 10 midweeks, rather than the six it used to. The Champions League will take up eight matchdays, with the spare two used to give the Europa League and Conference League their own standalone weeks. Only the Champions League will play on the week of Sept. 17-19, with the Europa League taking Sept. 25-16 and the Conference League on the week of Dec. 19.

The Champions LEague league phase will now finish in January, rather than December, with six games played before Christmas and the last two rounds on Jan. 21-22 and Jan. 29.

With the new format producing multiple Pot 1 fixtures, when in previous seasons there wouldn't be any at all, UEFA hopes to create a spread of "marquee" matches across the matchdays. Our mock draw showed how these could appear across matchdays and how regular they would be, with only one week not having a meeting of two of the modern-day powerhouses.

How do the knockout rounds and the bracket work?

UEFA used to hold draws throughout the knockout rounds, but the new tennis-style method of using the league ranking to build the bracket means just two are required: one for the knockout phase playoffs (Jan. 31), and another for the round of 16 (Feb. 21) to complete the bracket.

There is no country protection, so for instance, Liverpool could play Aston Villa in the round of 16. In past seasons, country protection remained in place until the quarterfinals.

The strength of teams in the expanded tournament means some heavyweight teams are likely to miss out on the top eight, and that could create some blockbuster ties early in the knockout stage.

The first draw creates the knockout phase playoff fixtures, with each team having two possible opponents.

Clubs ranked 9-16 play the second leg at home. From this point, the position in the bracket is set for these teams.

From the final positions in our league table, the following knockout phase playoff ties are possible.

At the end of the league phase the top eight clubs will each have four possible round-of-16 opponents, based upon the build of the knockout bracket.

Taking our league table, it would fit together like this:

Real Madrid (1) or Manchester City (2) would play:
Winners of one of the ties involving Paris Saint-Germain (17), AS Monaco (18), Benfica (15) and Sporting CP (16)

Barcelona (3) or Arsenal (4) would play:
Winners of one of the ties involving Stuttgart (19), Bologna (20), Juventus (13) and Atlético Madrid (14)

Bayer Leverkusen (5) or RB Leipzig (6) would play:
Winners of one of the ties involving Atalanta (21), FC Salzburg (22), Liverpool (11) and Borussia Dortmund (12)

Bayern Munich (7) or AC Milan (8) would play:
Winners of one of the ties involving Girona (23), PSV Eindhoven (24), Inter (9) and Aston Villa (10)