  We make variational estimates for the binding energies of
$^2H,~^3H,~^4He,~^{16}O,~^{40}Ca$, showing their running with the Similarity
Renormalization Group (SRG) cutoff towards the infrared region and show the
generalized Tjon lines that emerge from the calculations. We infer the SRG
evolution of the three-body contributions for the $^3H$ and $^4He$ binding
energies by computing the two-body contributions with a variational approach
assuming that four-body forces are negligible. At any given SRG cutoff, the
three-body contributions may then be inferred as being the experimental value
minus the two-body contributions. The off-shell / on-shell transition at a
critical SRG cutoff $\lambda_c$ drives the behavior of all binding energies and
this scale is the turning point of the generalized Tjon lines. Also, at
$\lambda_c$ the ratios between three-body and two-body contributions to the
binding energies, $B_{\lambda_c}(3) ~/~ B_{\lambda_c}(2)$, are the same in both
$^3H$ and $^4He$ systems and equal to $1/4$, so that $B_{\lambda_c}(2) ~=~
4~B_{\lambda_c}(3)$. All calculations are carried out with the Idaho-Salamanca
N3LO potential, which is evolved with the SRG up to the infrared fixed point
($\lambda \to 0$) in all S, P, D, F and G partial-wave channels in order to
compute the variational binding energies at several SRG cutoff scales.
