Fraction of simulated and observed systems as a function of age judged as “near-resonant” according to the empirical criterion from Dai et al. (2024). Colored lines are each of our simulation suites, including extrapolation to 5 Gyr (see text) and the black line is the Dai et al. (2024) analysis of the observed young and field transiting systems. Nearly all systems leave the gas disk phase as resonant chains. As these chains break, fewer planet pairs are seen to be near resonance, although even non-resonant systems are sometimes determined to be near-resonance coincidentally.