For 
,
The strict-dominant probabilities lie on a curve indexed by p and joining 
and 
. Note that these IBD probabilities are independent of 
and are very close to the line 
. The strict-dominant and strict-recessive curves intersect at the point 
, which corresponds to the IBD probabilities for a strict-recessive model with 
and a strict-dominant model with 
(Louis et al. [21]).