Well, more layers of the onion are being peeled. I decided to check my bracket's scores after round one.
While I appear to have gotten +43 and my opponent -43, the other three winners only got +42. Two of the losers besides my opponent got -43, but one got -42. I can't find a reason for the discrepancy. I had slightly lower GP than my opponent, and the other player with the extra point had the lowest GP in the bracket. The difference is, they lost. The other two pairs should show one or both of these patterns, but they don't, so that can't be it. Likewise, in the bracket that was posted yesterday, there's no consistent GP pattern to the extra points.
My opponent scored a 0, but again, this can't be what happened in the other match as the loser gained an extra point. Why did Deadspace gain an extra point for losing in the other bracket on a round where they did NOT post a 0? So no pattern there.
What I can tell you is that SR does NOT determine ranking within brackets; only record does. I have the highest SR now by 1, but my rank is listed as #2. The extra point loser should be #5 by SR, but they are #7.
So, not sure about the points. A thought occurs to me that SRs could have decimal values to them that aren't displayed. This might help explain global leaderboard rankings, but as I've demonstrated, it doesn't affect within-bracket rankings.