The catalogue does not identify a separate base return. RTP Ledger leaves the base return unknown. Use the mode table for the published values.
At the two-decimal display precision, 360 modes share the highest displayed RTP of 96.05%: balls100 gold left r08 expert, balls100 gold left r08 high, and balls100 gold left r08 low and 357 more. 360 modes share the lowest displayed RTP of 96.05%: balls100 gold left r08 expert, balls100 gold left r08 high, and balls100 gold left r08 low and 357 more. The difference between the displayed extremes is 0 percentage points.