Your Contest Flashback ROI is different than the Sim ROI you see in your builds because lineups in the contest are different.
When SaberSim runs a contest sim on a lineup, it takes your lineup that we are calculating the ROI for and runs it through a simulated version of a contest with a GPP payout structure.
To run the contest sim, it needs to fill out that contest with other realistic lineups for your lineup to compete against. When you’re building lineups on SaberSim before lock, the lineups that your lineup is competing against in the contest sim are what we project the field to play, based on the stakes, size, and entry fee of the contest. We use these projected fields because before lock, we don’t know exactly what your opponents will play.
After the slate is over, however, we do know exactly what your opponents played. Contest Flashback, instead of using projected fields, takes the real lineups your opponents played in your contests and runs the contest sims based on that, giving you a more accurate assessment of the ROI of your lineups against the lineups you actually faced. Because of this, Contest Flashback is a stronger signal to the overall profitability of your lineups than Sim ROI.
We put an extensive amount of work into our projected fields, and are constantly monitoring their accuracy and making improvements to them over time. But ultimately, they are only a projection, not a crystal ball, and will never match up to exactly what your opponents play. The bigger the disparity in the projected field and the actual field, the bigger the disparity between your Sim ROI and your Flashback ROI.