Makes my head hurt too! The numbers are all proven from years of tracking them in GTS. The easier wins in lower SR races is just from experience, im sure many others here will echo the sentiment. Exactly why that’s the case I’m not sure I could articulate.
@Sven Jurgens where are you! He’s the man for this discussion.
Lol, time for a recap I see
SR is the primary factor for matchmaking and works on a scale of 1 to 99.
You generally gain 0.3 to 0.4 SR for each clean sector you complete (actual amount depends on the race). Generally the longer the race, or rather the higher the total number of sectors, the more SR you can gain in a race. It can be as low as 3 SR total for a short sprint race or as high as 20 SR for a long race C.
You lose SR for contact with another car. This is not indicated anymore nowadays (no more SR Down arrows) so it's a bit of guess work what does trigger SR loss. If you get a contact penalty you lose 5 to 10 SR for that event. Without a penalty you lose 2 or 3 SR per contact.
SR ranges are E (1-9) D (10-19) C (20-39) B (40-64) A (65-79) S (80-99)
DR ranges are D (1-3,999) C (4,000-9,999) B (10,000-29,999) A (30,000-49,999) A+ (50,000-99,999)
Matchmaking works in ranges of 10 SR.
First the server collects all entries in 90-99 SR range, sorts them on DR and creates rooms from high to low DR.
Next it collects the entries in the 80-89 SR range, sorts them on DR and first adds the highest DR in this group to the left over spots in the last room of the previous group. Hence you can get A+/S together with D/S. The DR D player is in the 90-99 SR range, the A+ driver in the 80-89 range. It's a 'bug' that's been there since the beginning.
This works all the way down so it just keeps getting messier the further down the SR ranks matchmaking goes, and the lower the player count (available entries) gets. Say that last SR.S room still isn't full, next the highest DR SR A player gets added and so on.
The 80-89 range is a sweet spot for high DR players since they are likely to get added to the left over spots in the lowest DR room of the 90-99 SR players. Dropping below 90 SR means pole position and victory for high DR players. SR S is the biggest group (Too easy to gain SR and PD doesn't deduct SR for 90% of contacts) hence the sweet spot since it's the most likely place where there is a 'last room' with low DR players.
Another reason why races are easier in lower SR -> less aliens. In the top split you're always matched with the fastest A+ drivers who generally stick to SR.S. Those that value their DR the most will do anything to stay above SR.B since dropping 1.5 levels in SR below your DR letter means your DR will get reset to halfway the closer DR letter.
Drop below 50 SR as DR A+ and you'll be reset to 40K DR A.
Drop below 30 SR as DR A and you'll be reset to 20K DR B.
Drop below 15 SR as DR B and you'll be reset to 7K DR C.
Drop below 5 SR as DR C and you'll be reset to 3K DR D.
Your DR letter cannot advance past your SR letter. However that's of little consequence, you still gain DR and you still get matched on your numerical DR. You can have 35K DR and still be labeled DR.B if your SR has remained at B or lower. Once you reach SR A, your DR letter will be updated and then you get the 1,500 DR bonus for going up a rank. (Going down a rank you lose an extra 1,500 DR, unless you lost rank(s) by getting a DR reset)
