Synthetic, single-period returns. Each weight slider sets segment A; segment B gets the remainder.

One segment as areas · weight × return, in basis points

The outer rectangle is the portfolio in the segment, the grey area the benchmark. Hatched areas count negatively.

Segment A · effects in basis points

Segment B · effects in basis points

Total · effects in basis points

Switching 1985 ↔ 1986 changes segment allocations; their sum is unchanged. Absorbing interaction into selection changes those totals by convention.