The difference in the peak polar field in consecutive solar cycles varies with different parameters of BMRs as:
1. TILT ANGLE:
Standard tilt angle: 19 degrees (van Ballegooijen et al.)
Standard separation: Unknown
3. NO. OF SUNSPOTS PER CYLCLE:
Standard no. of sunspots per cycle: Unknown
Observations show the difference in the peak polar field to be around 20 Gauss. Now, several combinations of variations in these parameters can lead us to that difference.