Not how it works. Every game uses only your SR (or maybe MMR based on how old the information is, and MMR and SR go up and down together except for decay and disconnect penalties) to determine who you should play against. Your streaks are far more likely to be psychological.
There is no rigging.
There are no enforced wins or losses.
The only thing win / loss chance is used for is SR adjustment. If you win a game that was in your favor, you gain a little less SR. If you lose a game you should have won, you lose a little more SR than normal. Normal is 24 SR.